* Add pull requests guide doc
Co-Authored-By: NRyan Lucia <ryan@luciaonline.net>
Co-authored-by: NRyan Lucia <ryan@luciaonline.net>
Co-authored-by: NDan Moseley <danmose@microsoft.com>

These nodes didn't do anything.

Became orphaned in #172.

Based on offline chat with JanV I added initial provisions to simplify
diffing Crossgen1- and 2-compiled SPC. In essence, the --diff option
newly ends up emitting two extra files with the ".r2rdump" extension
representing the methods common to the left and right R2R file. This
is formerly untrodden territory, I'm pioneering R2RDump usability for
this purpose.

Thanks

Tomas

Fixes mono/mono#18554 by making autoconf actually check if `-mminimal-toc` works instead of assuming on powerpc. Tested with FreeBSD 12.x and 13.x on powerpc64 ELFv2.
While we are in here, also enable BTLS which has passed testing. 
Co-authored-by: NPhil Jaenke <prj@rootwyrm.com>

This is used by the SplashScreen class of WindowsBase in .NET Core to pass a NULL pointer.
Co-authored-by: NVincent Povirk <madewokherd@gmail.com>

Fixes #1232

[runtime] Disable lldb backtrace display on osx, it hangs on attaching in lldb.

This fixes two things:
* UseJitPath on compilation builder doesn't make sense for any other backends this file is shared with (CppCodegen/LLVM). Moving that to ReadyToRunCodenCompilationBuilder.
* JitConfigProvider made it look like a configurable JIT path and configurable COMPlus RyuJIT options are a thing, but they're in fact per process and can only be initialized once (first is an implementation limitation in CorInfoImpl, the second is a RyuJIT limitation). Making the config class static+throwing for double-initialization to make this very clear.

[debugger] Access invalid memory address using PointerValue Command.

Creating a fork process to access address that came from IDE using PointerValue. The IDE can send an invalid address and it was crashing mono.

Fixes mono/mono#18191

* CPU utilization computation fixes
- On Unix, move scalling for total number of processors from PAL to managed side, so that it can use container limit aware ProcessorCount
- Delete asserts for CPU utilization being between 0 and 100. These asserts can fail due to races or rounding errors.
- Converted a few classes to structs

Fixes #2195

* Fix buildbreak

Co-authored-by: NMaher Jendoubi <maher.jendoubi@gmail.com>

I recently wrote a large, exhaustive set of tests to validate our handling of regex character sets.  Unfortunately it ends up being too much for our CI system.  We were validating ~440 different character sets, for both RegexOptions.None and RegexOptions.Compiled, and for each validating all 65,536 character inputs... that's ~58M regex matches.  In most cases locally it was taking around 15s, but on a loaded, underwhelming CI machine, it was taking minutes in some cases.

I've reduced the load (primarily by only validating the specified characters that should be included or excluded in cases where we're already testing both the positive and negative variants of the same set), while trying to keep a reasonable semblence of the coverage.

I also made it outerloop, and moved a few other longer-running regex tests to outerloop as well.

The abstract types SHAx and MD5 did not set HashSizeValue, which
would lead to derived types to have HashSize a value of 0. This
initializes the field to match .NET Framework behavior.

[jit] Compute has_references correctly for gshared types whose constraint is a generic valuetype.

* Fix intrinsics treatment in Crossgen2

This change fixes unintentional differences in the treatment of
intrinsics in Crossgen2 compared to Crossgen1 I found while
investigating failures in the regression test b426654. While the
change by itself doesn't fully fix the test, I believe it to be
generally useful towards removing the remaining codegen
differences between the compilers.

Thanks

Tomas

* Address JanK's PR feedback

I have audited all entries in the intrinsics table and I added
the [Intrinsic] annotation to all applicable methods. I haven't
found <code>System.EETypePtr.EETypePtrOf</code> and
<code>System.Activator.DefaultConstructorOf</code> anywhere.
I have reverted the additional check for IsInternalCall that
I put in CorInfoImpl in the 1st commit.

Thanks

Tomas

* Revert assertion check for IsInternalCall

* Remove superfluous check for the intrinsic attribute

* Put back the CORINFO_FLG_JIT_INTRINSIC flag

* Remove superfluous namespace name on Intrinsic per JanK's suggestion

* One more removal of superfluous namespace specification

* Move Strings.resx from CoreCLR to shared System.Private.CoreLib folder

Mono and CoreCLR both use the same file.

* Get rid of duplicate string

[runtime] Avoid loading ThreadAbortException class on netcore.

This gives us a single method that controls most of the jit's phase behavior.
Largely a manual inline, though I updated some comments and changed one assert.

Follow up from #1309; also see #2109.

Need to also report the hidden return buffer pointer as GC live, in case it
happens to refer to a heap location (method invoked via reflection).

Also did some minor cleanup; we weren't using `returnsGCr` in `emitEndCodeGen`
and we were munging return value liveness unnecessarily when not emitting
a profiler leave hook.

Closes #1971.

* Refactor CMake system to allow cross OS DAC compile

Add CLR_CMAKE_HOST_OS

Add rules to determine which cross OS combinations are valid

Make add_definitions depend on TARGET OS properties. Wherever reasonable 
make C++ defines depend on runtime target rather than host.

Initial CMAKE build system support for Mono.

Matches what we do for uninstatiated generic types - no need to look at generic parameters.

* Remove date number from dev build version

* Set Library assembly version back to 5.0.0.0

* Use default assembly version in versions.props and fix package testing

* Add missed change to define AssemblyVersion to match MajorVersion.MinorVersion.0.0 in the root

* Don't change AssemblyVersions in installer, leave as it was

* Fix installer tests

* Move AssemblyVersion for installer test assets to right place
Co-authored-by: NSantiago Fernandez Madero <safern@microsoft.com>

* corefx => runtime

* Update adding-api-guidelines.md

* Update adding-api-guidelines.md