* Fix assert 'treeWithCall == call'

This assert was occurring when we have:
- a potential optimistic tail call
- of a function that returns a ref type
- that is also an inline candidate
- whose inline is rejected
- with `COMPlus_JitGCChecks` stress mode that injects a
call to `CORINFO_HELP_CHECK_OBJ` at the `RETURN`
- where we decide to go ahead with the optimistic tailcall
but it is no longer in legal tailcall position.

To fix, simply disallow a tailcall if we are doing
`COMPlus_JitGCChecks` in a function with a ref type return, that
would have inserted the problemmatic call.

Fixes #1821

* Fix formatting

* Make sure CoreCLRArtifactsPath/MonoArtifactsPath has trailing slash

Addresses the official build break caused by the Mono CI PR.

Fixes https://github.com/dotnet/runtime/issues/2053

* Handle empty RuntimeArtifactsPath

Fixes #483. Structs with pointer-typed fields are blittable.

After #1866 we no longer have to worry about the recursion because the code path that recursed into pointed-to types was deleted.

Remove "handles" from System.Threading.Semaphore.
Co-Authored-By: NJay Krell <jaykrell@microsoft.com>

* begining -> beginning

* paramterized -> parameterized

* folow -> follow

* occurance -> occurrence

* Fix bad changes

* Apply suggestion + minor space fix

* Fix for issue #1740

U+0085 not recognised as a newline character in CSharpCodeGenerator.cs

Fix $1740

* Fix for issue #1740

U+0085 not recognised as a newline character in CSharpCodeGenerator.cs

* Fix for issue #1740

U+0085 not recognised as a newline character in CSharpCodeGenerator.cs
This change fixes a previous test that incorrectly causes the character to be forced out of being in unicode format.

* Stop the changes from #1740 on the .Net Framework as per #1913

Read #1913 for why, view PR #1853 and #1740 also.

[debugger] Native thread not executing managed code considered as terminated 

Fixes mono/mono#18417

[jit] Compute the instance size/alignment correctly for gshared types whose constraint is a generic valuetype. (#2034)

Fixes mono/mono#18455

* Add workaround for ILLinker stripping COM interop details

Fixes #1264

* Correct version of the fix

It's not needed in dotnet/runtime.

* Improve markdown file

* Revert the ol to ul change

If a thread was suspended and doesn't have any managed stack, it was considered as terminated, but it wasn't really terminated because it can execute managed code again, and stop in a breakpoint so if the execution arrives in debugger_agent_breakpoint_from_context we reset the flag terminated to FALSE.

Fixes #18106

`jit_tls->interp_context` gets initialized lazily, that is, upon the first interpreter execution on a specific thread (e.g. via interp_runtime_invoke). However, with mixed mode the execution can purely happen in AOT code upon the first interaction with the managed debugger.

Stack trace:

```
  thread #1, name = 'tid_407', queue = 'com.apple.main-thread'
    frame #0: 0x0000000190aedc94 libsystem_kernel.dylib`__psynch_cvwait + 8
    frame #1: 0x0000000190a0f094 libsystem_pthread.dylib`_pthread_cond_wait$VARIANT$armv81 + 672
    frame #2: 0x000000010431318c reloadcontext.iOS`mono_os_cond_wait(cond=0x0000000104b9ba78, mutex=0x0000000104b9ba30) at mono-os-mutex.h:219:8
    frame #3: 0x0000000104312a68 reloadcontext.iOS`mono_coop_cond_wait(cond=0x0000000104b9ba78, mutex=0x0000000104b9ba30) at mono-coop-mutex.h:91:2
    frame #4: 0x0000000104312858 reloadcontext.iOS`suspend_current at debugger-agent.c:3021:4
    frame #5: 0x000000010431be18 reloadcontext.iOS`process_event(event=EVENT_KIND_BREAKPOINT, arg=0x0000000145d09ae8, il_offset=0, ctx=0x0000000149015c20, events=0x0000000000000000, suspend_policy=2) at debugger-agent.c:4058:3
    frame #6: 0x0000000104310cf4 reloadcontext.iOS`process_breakpoint_events(_evts=0x000000028351a680, method=0x0000000145d09ae8, ctx=0x0000000149015c20, il_offset=0) at debugger-agent.c:4722:3
    frame #7: 0x000000010432f1c8 reloadcontext.iOS`mono_de_process_breakpoint(void_tls=0x0000000149014e00, from_signal=0) at debugger-engine.c:1141:2
    frame #8: 0x000000010430f238 reloadcontext.iOS`debugger_agent_breakpoint_from_context(ctx=0x000000016f656790) at debugger-agent.c:4938:2
    frame #9: 0x00000001011b73a4 reloadcontext.iOS`sdb_breakpoint_trampoline + 148
    frame #10: 0x00000001008511b4 reloadcontext.iOS`reloadcontext_iOS_Application_Main_string__(args=0x000000010703a030) at Main.cs:14
    frame #11: 0x00000001010f9730 reloadcontext.iOS`wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 272
    frame #12: 0x00000001042fd8b8 reloadcontext.iOS`mono_jit_runtime_invoke(method=0x0000000145d09ae8, obj=0x0000000000000000, params=0x000000016f656f20, exc=0x0000000000000000, error=0x000000016f656ff8) at mini-runtime.c:3162:3
    frame #13: 0x0000000104411950 reloadcontext.iOS`do_runtime_invoke(method=0x0000000145d09ae8, obj=0x0000000000000000, params=0x000000016f656f20, exc=0x0000000000000000, error=0x000000016f656ff8) at object.c:3052:11
    frame #14: 0x000000010440c4dc reloadcontext.iOS`mono_runtime_invoke_checked(method=0x0000000145d09ae8, obj=0x0000000000000000, params=0x000000016f656f20, error=0x000000016f656ff8) at object.c:3220:9
    frame #15: 0x0000000104415ae0 reloadcontext.iOS`do_exec_main_checked(method=0x0000000145d09ae8, args=0x000000010703a030, error=0x000000016f656ff8) at object.c:5184:3
    frame #16: 0x00000001044144ac reloadcontext.iOS`mono_runtime_exec_main_checked(method=0x0000000145d09ae8, args=0x000000010703a030, error=0x000000016f656ff8) at object.c:5281:9
    frame #17: 0x0000000104414500 reloadcontext.iOS`mono_runtime_run_main_checked(method=0x0000000145d09ae8, argc=1, argv=0x000000016f6570d0, error=0x000000016f656ff8) at object.c:4734:9
    frame #18: 0x00000001042d3b54 reloadcontext.iOS`mono_jit_exec_internal(domain=0x0000000145f00130, assembly=0x0000000281ba2900, argc=1, argv=0x000000016f6570d0) at driver.c:1320:13
    frame #19: 0x00000001042d39a4 reloadcontext.iOS`mono_jit_exec(domain=0x0000000145f00130, assembly=0x0000000281ba2900, argc=1, argv=0x000000016f6570d0) at driver.c:1265:7
    frame #20: 0x0000000104597994 reloadcontext.iOS`::xamarin_main(argc=5, argv=0x000000016f657a80, launch_mode=XamarinLaunchModeApp) at monotouch-main.m:483:8
    frame #21: 0x00000001008510dc reloadcontext.iOS`main(argc=5, argv=0x000000016f657a80) at main.m:104:11
    frame #22: 0x0000000190af8360 libdyld.dylib`start + 4
[...]
* thread #5, name = 'Debugger agent', stop reason = signal SIGABRT
  * frame #0: 0x0000000190aedec4 libsystem_kernel.dylib`__pthread_kill + 8
    frame #1: 0x0000000190a0d724 libsystem_pthread.dylib`pthread_kill$VARIANT$armv81 + 216
    frame #2: 0x000000019095d844 libsystem_c.dylib`abort + 100
    frame #3: 0x00000001045871b4 reloadcontext.iOS`log_callback(log_domain=0x0000000000000000, log_level="error", message="* Assertion at ../../../../../mono/mini/interp/interp.c:7176, condition `context' not met\n", fatal=4, user_data=0x0000000000000000) at runtime.m:1213:3
    frame #4: 0x0000000104544fc8 reloadcontext.iOS`eglib_log_adapter(log_domain=0x0000000000000000, log_level=G_LOG_LEVEL_ERROR, message="* Assertion at ../../../../../mono/mini/interp/interp.c:7176, condition `context' not met\n", user_data=0x0000000000000000) at mono-logger.c:405:2
    frame #5: 0x000000010456093c reloadcontext.iOS`monoeg_g_logstr(log_domain=0x0000000000000000, log_level=G_LOG_LEVEL_ERROR, msg="* Assertion at ../../../../../mono/mini/interp/interp.c:7176, condition `context' not met\n") at goutput.c:134:2
    frame #6: 0x0000000104560598 reloadcontext.iOS`monoeg_g_logv_nofree(log_domain=0x0000000000000000, log_level=G_LOG_LEVEL_ERROR, format="* Assertion at %s:%d, condition `%s' not met\n", args="e\x12z\x04\x01") at goutput.c:149:2
    frame #7: 0x000000010456061c reloadcontext.iOS`monoeg_assertion_message(format="* Assertion at %s:%d, condition `%s' not met\n") at goutput.c:184:22
    frame #8: 0x0000000104560674 reloadcontext.iOS`mono_assertion_message(file="../../../../../mono/mini/interp/interp.c", line=7176, condition="context") at goutput.c:203:2
    frame #9: 0x000000010459b570 reloadcontext.iOS`interp_get_resume_state(jit_tls=0x000000014900d000, has_resume_state=0x000000016fc7a9f4, interp_frame=0x000000016fc7a9e8, handler_ip=0x000000016fc7a9e0) at interp.c:7176:2
    frame #10: 0x0000000104319420 reloadcontext.iOS`compute_frame_info(thread=0x0000000104fe4130, tls=0x0000000149014e00, force_update=1) at debugger-agent.c:3422:3
    frame #11: 0x0000000104320d40 reloadcontext.iOS`thread_commands(command=1, p="", end="", buf=0x000000016fc7acf8) at debugger-agent.c:9048:3
    frame #12: 0x000000010431cca0 reloadcontext.iOS`debugger_thread(arg=0x0000000000000000) at debugger-agent.c:10132:10
    frame #13: 0x000000010447eb04 reloadcontext.iOS`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=0x000000016fc7b000) at threads.c:1232:3
    frame #14: 0x000000010447e788 reloadcontext.iOS`start_wrapper(data=0x000000028203ef40) at threads.c:1305:8
    frame #15: 0x0000000190a11d8c libsystem_pthread.dylib`_pthread_start + 15
[...]
```

Thanks to @drasticactions for helping me to reproduce.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1050615

<!--
Thank you for your Pull Request!

If you are new to contributing to Mono, please try to do your best at conforming to our coding guidelines http://www.mono-project.com/community/contributing/coding-guidelines/ but don't worry if you get something wrong. One of the project members will help you to get things landed.

Does your pull request fix any of the existing issues? Please use the following format: Fixes #issue-number
-->
Co-authored-by: NBernhard Urban-Forster <bernhard.urban@xamarin.com>

* Address follow-up feedback from #1934

* Remove whitespaces

* Unify build_native via eng/native/build-commons
In order to add new platform, architecture, compiler or its newer
version, there are currently multiple places to update, which can be
deduplicated.

This patch unifies:

* directories creation
* prerequisites checking
* `version.c` generation
* native build invocation
* common argument parsing
* building help menu

for various build scripts under coreclr, installer and libraries.

The common entry-point script is now `eng/native/build-commons.sh` and
rest of the scripts under `eng/native` are implementation detail.

Also extracted CMake platform detection in
`eng/native/configureplatform.cmake`, to share with coreclr and
`installer/corehost`.

* Use if [[ cond ]] in all places

The jit was not extending return value liveness properly for methods that
returned a ref-wrapped struct, if jitstress caused code to be added between
the final body statement and the epilog (eg a profile leave hook).

Fixes many of the cases in #1971.

- Our CompilationModule groups used for single method compilation and general compilation had diverged substantially, reducing the effectiveness of single method compilation substantially
- The profiler guided optimization logic also needs to use the VersionWithCode logic to identify which methods are interesting to consider, this will happen in a future change
- The VersionsWith logic in CompilationModuleGroup did not correctly model versionable logic.
  - Methods with generic parameters were not handled correctly. Method generic parameters did not contribute to the VersionsWith logic.
  - The newer ideas in our recent work on upcoming enhancements to crossgen2 driven compilation enhancements are aligned with this effort
  - Add support for the concept of considering instantiations over primitive types to be legal even if the primitive types aren't part of the version bubble. (Only if there are no constraints in the generic)

- Also a bonus determinism fix. In cases where MemberRef's were being used in combination with ENCODE_FIELD_SIG_OwnerType, we could possibly emit multiple different choices for the token emitting in a signature.

Change HostPolicyMock to use CharSet.Auto now that it correctly switches to Ansi (aka Utf8) on non-Windows. (#2031)

* Don't block non-blittable pointer types in P/Invokes.

Don't block non-blittable pointer types in P/Invokes. If you're using pointers in interop you're already using unsafe code so we're going to assume you know what you're doing. C# won't let you form a pointer to a reference, so there's no risk of passing an object reference directly to native unless you're writing IL directly.

Fixes dotnet/coreclr#27800

* Delete unused resources.

* Apply fix to managed type system as well.

* Add positive test for nonblittable pointers. Remove negative tests that were in GenericTest.

* Rename PAL_CMAKE_* CLR_CMAKE_*

Remove separatation between CLR_CMAKE and PAL_CMAKE defines

Revise PAL_CMAKE_PLATFORM* defines to use CLR_CMAKE_HOST* defines

Revise other PAL_CMAKE_* defines to use CLR_CMAKE_* equivalents.

Remove redundant compiler configuration

host: Allow comments in JSON files

The Configurations.props file was modified to have $(NetCoreAppCurrent)-Linux and
$(NetCoreAppCurrent)-OSX instead of $(NetCoreAppCurrent)-Unix in a recent PR #427,
but the Configurations in the System.Net.Quic.csproj were not updated accordingly.

* add RunImpersonateAsync overloads

* skip on full framework

* run test netcoreapp only

* skip tests on nanoserver

* address PR feedback

* address PR feedback

* address PR feedback

* address PR feedback

* Update WindowsIdentity.cs

update comment

* Update WindowsIdentity.cs

update comment

* Update WindowsIdentity.cs

Fix comment

* Update WindowsIdentity.cs

fix comment

* Fix comment

configure.ac: remove AC_SEARCH_LIBS for libintl

Actually, there were no handles.
This reduces MonoError.

Same type can be loaded by multiple threads in parallel in rare situations

Fixes #1847

* Update dependencies from https://github.com/dotnet/arcade build 20200115.5

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.20065.5
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.20065.5
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.20065.5
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20065.5
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.20065.5
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.20065.5
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.20065.5
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.20065.5
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.20065.5
- Microsoft.DotNet.GenAPI - 5.0.0-beta.20065.5
- Microsoft.DotNet.GenFacades - 5.0.0-beta.20065.5
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.20065.5
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.20065.5
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.20065.5

* Update dependencies from https://github.com/dotnet/arcade build 20200116.1

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.20066.1
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.20066.1
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.20066.1
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20066.1
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.20066.1
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.20066.1
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.20066.1
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.20066.1
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.20066.1
- Microsoft.DotNet.GenAPI - 5.0.0-beta.20066.1
- Microsoft.DotNet.GenFacades - 5.0.0-beta.20066.1
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.20066.1
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.20066.1
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.20066.1

* Update dependencies from https://github.com/microsoft/vstest build 20200116-01

- Microsoft.NET.Test.Sdk - 16.5.0-preview-20200116-01

* Update dependencies from https://github.com/dotnet/arcade build 20200117.2

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.20067.2
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.20067.2
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.20067.2
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20067.2
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.20067.2
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.20067.2
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.20067.2
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.20067.2
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.20067.2
- Microsoft.DotNet.GenAPI - 5.0.0-beta.20067.2
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.20067.2
- Microsoft.DotNet.GenFacades - 5.0.0-beta.20067.2
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.20067.2
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.20067.2

* Update dependencies from https://github.com/dotnet/arcade build 20200118.1

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.20068.1
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.20068.1
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.20068.1
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20068.1
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.20068.1
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.20068.1
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.20068.1
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.20068.1
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.20068.1
- Microsoft.DotNet.GenAPI - 5.0.0-beta.20068.1
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.20068.1
- Microsoft.DotNet.GenFacades - 5.0.0-beta.20068.1
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.20068.1
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.20068.1

* Update dependencies from https://github.com/microsoft/vstest build 20200120-01

- Microsoft.NET.Test.Sdk - 16.5.0-preview-20200120-01

* Update dependencies from https://github.com/dotnet/arcade build 20200121.3

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.20071.3
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.20071.3
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.20071.3
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20071.3
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.20071.3
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.20071.3
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.20071.3
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.20071.3
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.20071.3
- Microsoft.DotNet.GenAPI - 5.0.0-beta.20071.3
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.20071.3
- Microsoft.DotNet.GenFacades - 5.0.0-beta.20071.3
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.20071.3
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.20071.3

We go out of our way (e.g. on Unix queueing work off of the epoll threads) to ensure that arbitrary user code running as part of socket continuations doesn't block those threads and potentially deadlock.  Add a test to help validate this.

This leads us to generate an illegal relocation fixup.

Fixes #1789

Although JSON doesn't support comments, a common extension is to enable
JavaScript-style comments.  By default, RapidJSON will error out if
comments are found in the input data, but it can be configured to
ignore them.

This is useful especially when testing out changes in
runtimeconfig.json files.

Fixes http://github.com/dotnet/core-setup/5661

* Avoid extra field loads / comparisons in FindFirstChar

If we've already compared the current pos to the end pos as part of a minimum length check, we don't need to repeat it again later.  We can also read from locals rather than fields more than we are to save redundant field reads.

* Reduce branches in Boyer-Moore negative switch table

It's often the case that lots of negative branches have the same value.  We can coalesce them.

* Address PR feedback