* Implement NativeMemory

* Exposing additional APIs as approved

* Ensure we have a test covering alignment and size being less than sizeof(void*)

* Update src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeMemory.Unix.cs
Co-authored-by: NJan Kotas <jkotas@microsoft.com>

* Responding to PR feedback

* Adding additional alignment test coverage for 1 to 16384

* Add coverage for 65k and 1/2/4MB alignments

* Fixing the Native\Unix\System.Native\CMakeLists.txt

* Update src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeMemory.Unix.cs
Co-authored-by: NJan Kotas <jkotas@microsoft.com>

* Don't call Buffer.Memmove in NativeMemory.AlignedRealloc if ptr is null

* Updating NativeMemory.AlignedRealloc to correctly copy only the size of the last allocation

* Ensure check_symbol_exists(HAVE_ALIGNED_ALLOC) is under the non-apple paths

* Check for malloc_usable_size in malloc_np for FreeBSD and ensure tests compile

* Fix the ReallocSmallerToLargerTest test

* Handle that posix_memalign differs from aligned_alloc for size == 0
Co-authored-by: NJan Kotas <jkotas@microsoft.com>

* Only include Microsoft.NET.Runtime.RuntimeConfigParser.Task on mobile

* Add maccatalyst target imports per request

The array is only used for a subset of validators; no point in paying for this array for every ValidationState instance even if it's not going to be used.

* Add CodeSign to HostWriter

* Fix test

* PR feedback

* Add EnableMacOSCodeSign to CreateAppHost
Add tests

* Check that OSPlatform is OSX before running codesign.

* Guard from filepaths containing spaces

* Move apphost exceptions to a single file
Modify apphost exceptions inheritance

* Move AppHostUpdateException

* Apply suggestions from code review
Co-authored-by: NJan Kotas <jkotas@microsoft.com>

* Add exit code to AppHostSigningException
Co-authored-by: NJan Kotas <jkotas@microsoft.com>

I noticed a bunch of failures trying to run crossgen2 on these binaries
in one of our collections.

Also, make the checking case-insensitive: I saw that we were failing to
match "corerun.exe" against "CoreRun.exe" that was in the exclusion list.

* Add a test for Expression.Property and its handling of property accessors

This mostly a linker test as this effectively validates linker feature from https://github.com/mono/linker/pull/1880.

But having a clean trimming tests here is better validation for this specific case.

* Add one more test case as per feedback

* Remove debugging leftover

Enables nearly all disabled `JIT/HardwareIntrinsics` tests.
`StoreNonTemporal_{r,ro}` and `Sse42.X64/Crc32_{r,ro}` remain disabled due to
issues that are out of scope for this PR.

Changes:

* Enable `pclmul` and `aes` when AOT compiling runtime tests.


* Add a `immediate_unroll_unreachable_default`, used to mark the default case
  in an unrolled immediate switch as unreachable.


* Fix `OP_MULX_HL{32,64}`: the low-word address is sometimes an integer produced
  by ptrtoint

  Fixes compilation of `JIT/HardwareIntrinsics/X86/Bmi2/Bmi2_{r,ro}/**`
  and `JIT/HardwareIntrinsics/X86/Bmi2.X64/Bmi2.X64_{r,o}/**`.


* Implement immediate unrolling for `Ssse3.AlignRight`

  Fixes `JIT/HardwareIntrinsics/X86/Ssse3/Ssse3_{r,ro}/**`.


* Implement the 3-argument overload of `Bmi1.BitFieldExtract`

  Fixes `JIT/HardwareIntrinsics/X86/Bmi1/Bmi1_{r,ro}/**` and
  `JIT/HardwareIntrinsics/X86/Bmi1.X64/Bmi1.X64_{r,ro}/**`.


* Implement immediate unrolling for `Aes.KeygenAssist`

  Fixes `JIT/HardwareIntrinsics/X86/Aes/Aes_{r,ro}/**`.


* Implement immediate unrolling for `Sse41.MultipleSumAbsoluteDifferences`

  Fixes
  `JIT/HardwareIntrinsics/X86/Sse41/MultipleSumAbsoluteDifferences_{r,ro}/**`.


* Mask vector selection index in `OP_XEXTRACT_*` and `OP_XINSERT_*`

  LLVM `insertelement` and `extractelement` yield poison values for lane
  indices that are out of bounds, but the underlying instructions on amd64 only
  care about the lower few bits in the immediate octet and the
  `Extract.UInt64.129` etc. tests in
  `JIT/HardwareIntrinsics/X86/Sse41.X64/Sse41.X64_r` test for this.

  Also, rename `OP_SSE41_INSERT` to `OP_SSE41_INSERTPS` and specialize this to
  the `insertps` overload of `Sse41.Insert`.

  Implement immediate unrolling for `OP_SSE41_INSERTPS`.

  Fixes `JIT/HardwareIntrinsics/X86/Sse41.X64/Sse41.X64_{r,ro}/**` and .
  `JIT/HardwareIntrinsics/X86/Sse41/Sse41_{r,ro}/**`.


* Copy the upper lanes over to the destination in `OP_SSE_CMPSS` and `OP_SSE2_CMPSD`

  Also fix the overloaded types associated with SSE saturating arithmetic LLVM
  intrinsic functions.

  Fixes `JIT/HardwareIntrinsics/X86/Sse2/Sse2_{r,ro}/**` and
  `JIT/HardwareIntrinsics/X86/Sse/Sse_{r,ro}/**`.


* Implement immediate unrolling for `Pclmulqdq.CarrylessMultiply`

  Fixes `JIT/HardwareIntrinsics/X86/Pclmulqdq/Pclmulqdq_{r,ro}`.

Change #53567 introduced new functionality to the JIT-EE
resolveVirtualMethod() API. This fixes the SuperPMI implementation
in the case where the API returns `false`, where some data fields
are not initialized.

Fixes crossgen2 SuperPMI collections.

Fixes #54310

* Remove unnecessary cost from XmlNode.SelectSingleNode

It's currently implemented by delegating to SelectSingleNodes and returning the first one.  While the list is lazily-populated, this still entails creating an `XPathNodeList`, creating a `List<XmlNode>`, storing the enumerated into the list, and then returning the element from the list, which is then thrown away.  With just a few lines, we can cut through all of that.

* Make XPathScanner and XPathParser into structs

No need for these to be allocated classes.  They can just live on the stack where they're created.

* Reduce ScanName overhead

This shows up on the hot path of parsing the xpath expression.  We can use a span to avoid bounds checking.

* Avoid bounds check in NextChar

NextChar is used by lots of routines to advance to the next character.  We can streamline it to avoid the bounds check when indexing into the string.

* Optimize SkipSpace for there not being any

The typical case is there isn't any whitespace, so inline that fast check.  This was showing up as a few percentage of a simple scenario.

* Delete invalid assert in PathInternal.CaseSensitivity

* Update PathInternal.CaseSensitivity.cs

* Resolving first part of System.Drawing.Common IlLink warnings

* Address PR feedback
Co-authored-by: NEric Erhardt <eric.erhardt@microsoft.com>

* Add PipeWriter CanGetUnflushedBytes and UnflushedBytes properties and covering tests

* address feedback

* [metadata] Cleanup redundant logic

Follow-up to 4e03f366

* Add m_method_is_abstract and m_method_is_final accessors

The kernel requires the function table to be 4-byte aligned.

* [interp] Fix comparisons between non runtime types

We know that the result of object.GetType and ldftn + GetTypeFromHandle are runtime types and we track it on the compilation stack. If type equality operator is applied on two runtime types we use reference equality comparison, otherwise we use the managed implementation which uses Type.Equals.

* [mini] Fix comparisons between non runtime types

We know that the result of object.GetType and ldftn + GetTypeFromHandle are runtime types and we track it on the compilation stack. If type equality operator is applied on two runtime types we use reference equality comparison, otherwise we use the managed implementation which uses Type.Equals.

* [interp] Resolve GetType on constrained valuetype to the actual type

The variable live range output is unnecessarily verbose. Simplify it; clean it up;
make it smaller; use standard dumpers.

Example, before:
```
////////////////////////////////////////
////////////////////////////////////////
Variable Live Range History Dump for Block 2
IL Var Num 0:
[rcx [ (G_M13669_IG02,ins#0,ofs#0), (G_M13669_IG03,ins#1,ofs#2) ]; rbp[16] (1 slot) [ (G_M13669_IG03,ins#1,ofs#2), NON_CLOSED_RANGE ]; ]
IL Var Num 1:
[rsi [ (G_M13669_IG03,ins#1,ofs#2), NON_CLOSED_RANGE ]; ]
////////////////////////////////////////
////////////////////////////////////////
End Generating code for Block 2
```
After:
```
Variable Live Range History Dump for BB02
V00 this: rcx [(G_M13669_IG02,ins#0,ofs#0), (G_M13669_IG03,ins#1,ofs#2)]; rbp[16] (1 slot) [(G_M13669_IG03,ins#1,ofs#2), ...]
V01 loc0: rsi [(G_M13669_IG03,ins#1,ofs#2), ...]
```

And the end-of-dump output, before:
```
////////////////////////////////////////
////////////////////////////////////////
PRINTING VARIABLE LIVE RANGES:
IL Var Num 0:
[rsi [18 , B5 )rsi [100 , 13A )rsi [14D , 186 )rsi [196 , 1C5 )rsi [1E3 , 271 )rsi [280 , 285 )]
IL Var Num 1:
[rdi [18 , B9 )rdi [100 , 137 )rdi [14D , 184 )rdi [196 , 1C2 )rdi [1E3 , 271 )rdi [280 , 288 )]
IL Var Num 2:
[rbx [18 , CA )rbx [100 , 10D )rbx [14D , 15A )rbx [196 , 1C7 )rbx [1E3 , 271 )rbx [280 , 28B )]
IL Var Num 3:
[rbp [3A , F0 )rbp [100 , 141 )rbp [14D , 18C )rbp [196 , 1D6 )rbp [1E3 , 275 )]
IL Var Num 4:
[r14 [3E , EC )r14 [100 , 13D )r14 [14D , 188 )r14 [196 , 1D2 )r14 [1E3 , 271 )]
IL Var Num 5:
[rcx [22A , 263 )]
////////////////////////////////////////
////////////////////////////////////////
```
After:
```
VARIABLE LIVE RANGES:
V00 arg0: rsi [18, B5); rsi [100, 13A); rsi [14D, 186); rsi [196, 1C5); rsi [1E3, 271); rsi [280, 285)
V01 arg1: rdi [18, B9); rdi [100, 137); rdi [14D, 184); rdi [196, 1C2); rdi [1E3, 271); rdi [280, 288)
V02 arg2: rbx [18, CA); rbx [100, 10D); rbx [14D, 15A); rbx [196, 1C7); rbx [1E3, 271); rbx [280, 28B)
V03 loc0: rbp [3A, F0); rbp [100, 141); rbp [14D, 18C); rbp [196, 1D6); rbp [1E3, 275)
V04 loc1: r14 [3E, EC); r14 [100, 13D); r14 [14D, 188); r14 [196, 1D2); r14 [1E3, 271)
V05 loc2: rcx [22A, 263)
```

csgen.1 also exists in src\tests\Regressions\coreclr\0582
simple1 also exists in src\tests\JIT\Directed\Arrays

This code only runs on macOS, and expects mono's System.Windows.Forms assembly is loaded into the process. This is causing trim warnings, and it is easier just to delete this code than try to make ILLink happy.

This code is only called from Graphics.FromHwnd, which doesn't work because the Carbon.framework no longer exists on macOS. Issue https://github.com/dotnet/runtime/issues/22221 is tracking the test failures that use FromHwnd.

* Improve cancellation in StreamPipeReader.ReadAtLeastAsync

* Introduce task variable
Co-authored-by: NStephen Toub <stoub@microsoft.com>

* Fix tests

* Expect TaskCanceledException on canceled token
Co-authored-by: NStephen Toub <stoub@microsoft.com>

Follow the same failure behavior for [ComImport] classes on Windows with built-in COM disabled as non-Windows. (#54298)

* Fix memory leak

* Update src/mono/mono/mini/mini-generic-sharing.c
Co-authored-by: NAleksey Kliger (λgeek) <akliger@gmail.com>

* Update src/mono/mono/mini/mini-generic-sharing.c
Co-authored-by: NAleksey Kliger (λgeek) <akliger@gmail.com>

* Fix the return
Co-authored-by: NAleksey Kliger (λgeek) <akliger@gmail.com>

* [wasm][aot][tests] Enable libraries that have been consistently passing

.. on the tracking PR.

- `System.Linq.Tests`
Fixes https://github.com/dotnet/runtime/issues/51722

- `System.Runtime.Extensions.Tests`
- `System.IO.Pipelines.Tests`
    - the failing tests have been disabled

* [wasm][aot][tests] Disable more tests that depend on stacktraces

.. in System.Runtime.Tests . The library is still disabled for AOT,
because it hasn't been stable only for the last 7 days.

* Re-enable System.Runtime.Loader.Tests which is passing now.

Read returning the number of bytes requested is not guaranteed.

Also dispose of AES usages to match behavior of the .NET Framework.

```
[22:22:31] fail: [FAIL] System.Tests.EnvironmentStackTrace.StackTraceDoesNotStartWithInternalFrame
[22:22:31] info: System.NullReferenceException : Object reference not set to an instance of an object.
[22:22:31] info:    at System.Reflection.RuntimeMethodInfo.Invoke(Object , BindingFlags , Binder , Object[] , CultureInfo )
```

Issue: https://github.com/dotnet/runtime/issues/51676