* Update dependencies from https://github.com/dotnet/arcade build 20191124.1

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.19574.1
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.19574.1
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.19574.1
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.19574.1
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.19574.1
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.19574.1
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.19574.1
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.19574.1
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.19574.1
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.19574.1
- Microsoft.DotNet.GenAPI - 5.0.0-beta.19574.1
- Microsoft.DotNet.GenFacades - 5.0.0-beta.19574.1
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.19574.1
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.19574.1

* Set installer.tasks to IsShipping=false

* Temporarily disable SymStore targets for System.Private.CoreLib

* Update dependencies from https://github.com/dotnet/arcade build 20191125.7

- Microsoft.DotNet.XUnitExtensions - 5.0.0-beta.19575.7
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.19575.7
- Microsoft.DotNet.VersionTools.Tasks - 5.0.0-beta.19575.7
- Microsoft.DotNet.ApiCompat - 5.0.0-beta.19575.7
- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.19575.7
- Microsoft.DotNet.Build.Tasks.Configuration - 5.0.0-beta.19575.7
- Microsoft.DotNet.Build.Tasks.Feed - 5.0.0-beta.19575.7
- Microsoft.DotNet.Build.Tasks.Packaging - 5.0.0-beta.19575.7
- Microsoft.DotNet.Build.Tasks.SharedFramework.Sdk - 5.0.0-beta.19575.7
- Microsoft.DotNet.CodeAnalysis - 5.0.0-beta.19575.7
- Microsoft.DotNet.GenAPI - 5.0.0-beta.19575.7
- Microsoft.DotNet.GenFacades - 5.0.0-beta.19575.7
- Microsoft.DotNet.Helix.Sdk - 5.0.0-beta.19575.7
- Microsoft.DotNet.RemoteExecutor - 5.0.0-beta.19575.7

* Add CoreLib shared source project

Add a CoreLib shared source project (shproj) to allow displaying shared
source files. With the move of the shared folder to a different location
VS isn't able to display the sources anymore. Adding a link attribute to
the compile items in the projitems fixes this but the information is
lost after a project reload. Therefore adding a shared project to the
solution.

* Update System.Private.CoreLib.Shared.shproj

* Update System.Private.CoreLib.Shared.shproj

* Avoid generating timeout checks for infinite timeouts

* Use Ldc_I4_X for Ldc when applicable

* Use ToLowerInvariant for invariant mode

* Remove unnecessary virtual-ness of some internal methods

* Clean up CompiledRegexRunner

* Lazily allocate RegexCharClass._categories

* Avoid negative numbers in generated names

* Optimize Is{ECMA}WordChar

* Optimize common CharInClass calls

* Clean up RegexCompiler.cs

* Add more RegexOptions.Compiled tests

* Replace RegexParser.s_category byte[] with a span

* Avoid delegate allocations each time CreateInstance is called

* Replace CharUnicodeInfo.GetUnicodeCategory w/ char's version

It has a fast path for ASCII.

* Clean up stackallocs

* Remove an unnecessary box

* Avoid string allocation for negated category

* Simplify tests

* Make low-hanging fruit allocation reduction

e.g. avoiding allocating a range list if a class contains only categories, avoiding some intermediary strings, avoiding some delegate allocations for sorting, etc.

* More code cleanup

* Use String.IndexOf in RegexParser.Unescape

Crossgen2 is failing to compile assemblies that contain reverse pinvoke
helpers with NotImplementedException.
This change fixes it by throwing RequiresRuntimeJit exception instead
for CORINFO_HELP_JIT_REVERSE_PINVOKE_ENTER and
CORINFO_HELP_JIT_REVERSE_PINVOKE_EXIT

[ 27%] Building CXX object src/pal/src/CMakeFiles/coreclrpal.dir/arch/amd64/signalhandlerhelper.cpp.o
coreclr/src/pal/src/thread/thread.cpp:1613:1: error: ‘CorUnix::PAL_ERROR CorUnix::InternalSetThreadDescription(CorUnix::CPalThread*, HANDLE, PCWSTR)’ has not been declared within CorUnix [-Werror]
 CorUnix::InternalSetThreadDescription(
 ^~~~~~~
In file included from coreclr/src/pal/src/include/pal/dbgmsg.h:160:0,
                 from coreclr/src/pal/src/thread/thread.cpp:21:
coreclr/src/pal/src/include/pal/thread.hpp:204:13: note: only here as a friend
             InternalSetThreadDescription(

In some cases we may end up in `lvaSetClass` without a valid ref class handle
from either the IR or the stack. Use the handle for `object` as a conservative
fallback.

Closes dotnet/coreclr#27923.

After change https://github.com/dotnet/coreclr/pull/27068 we
are creating multiple instances of CorInfoImpl. That broke the scenario
when jitpath is set: we are calling NativeLibrary.SetDllImportResolver
more than once, which results in
`System.InvalidOperationException: A resolver is already set for the assembly.`

This fix ensures that we call NativeLibrary.SetDllImportResolver
at most once.

This change also ensures that we set the resolver before attempting
to load the jit. That fixes the --jitpath scenario on Linux.

* Improve test coverage for RSAEncryptionPadding comparsion

* Simplify RSASignaturePadding comparison logic

* Consolidate sub-repo docs

Null delegates marshal as null pointers and vice versa.

Fixes https://github.com/dotnet/runtime/issues/185

Removed test scripts platform conditions to generate test wrappers.

* Stop transporting the test subtree as it shouldn't be actually
necessary.

* Clarify build phases in multi-subrepo world; unify script executions

* Unify the naming style for managed vs. native test artifacts

* Fix clangArg to be empty on Windows_NT

* Roll back unification of main product build script invocation

* Add CoreCLR prefix to test artifact name

* Proposed set of norms and best practices for issue and pull request management

* additional feedback

* additional feedback

* additional feedback

The importer was already optimizing away some array covariant store checks,
for cases where the value being stored was null, or the value being stored
came from the same array.

Change this to only optimize array covariant store checks in the importer
when optimization is enabled. For minopts, invoking the store helper produces
smaller code.

Update `gtGetClassHandle` to obtain the array handle from array newobjs,
and use this to also optimize cases where the destination array is exactly
`object[]` or is `T[]` where `T` is final and not itself subject to special
casting logic. In particular this gets the common case where `T` is `string`.

Closes dotnet/coreclr#6537.

* Allow project builds from script

* Fix installer builds

Fixes build breaks on CoreRT side.

It turns out it is not needed anymore, the assembly compiles fine

* Address some IDEXXX analysis warnings

* Address PR feedback

* Annotate System.IO.Compression.Brotli for nullable reference types

* Address PR feedback

* Fix AV in System.StubHelpers.CSTRMarshaler.ConvertFixedToNative

* Add test coverage

* Unifying many of the R2R and COR constants between crossgen2 and the r2rdump tools

* Move tools/crossgen2/Common to tools/Common

* Adjust paths in csproj files

* Initialize compSwitchedToOptimized and compSwitchedToMinOpts before calling to compInitOptions in jit/compiler.cpp

* Add LF to switchedToOptimized and switchedToMinOpts messages in jit/compiler.cpp

* Fix getting affinity set on MUSL on Jetson TX2

The code in PAL_GetCurrentThreadAffinitySet relied on the fact that the
number of processors reported as configured in the system is always
larger than the maximum CPU index. However, it turns out that it is not
true on some devices / distros. The Jetson TX2 reports CPUs 0, 3, 4 and
5 in the affinity mask and the 1 and 2 are never reported. GLIBC reports
6 as the number of configured CPUs, however MUSL reports just 4. The
PAL_GetCurrentThreadAffinitySet was using the number of CPUs reported as
configured as the upper bound for scanning affinity set, so on Jetson
TX2, the affinity mask returned had just two bits set while there were
4 CPUs. That triggered an assert in the GCToOSInterface::Initialize.

This change fixes that by looping over all cpu indices in the affinity set.
Similar fix went to GetProcessorForHeap and related stuff in gcenv.unix.cpp

These are left-over from .NET Native. Not needed for RyuJIT or Mono.

Fix crossgen2 handling of direct calls to abstract methods

It seems that the InvalidProgramException is more appropriate.

This change fixes two differences between old and new crossgen in the
getCallInfo method. Direct calls to abstract methods were being compiled
as if they were possible and lead to runtime crash in the call chain
from the PreStubWorker.

Fix missing unbox flag on method handle for struct methods