SVE: Match, NoMatch

[dhartglassMSFT]

Partially contributes to #94021

  /// T: sbyte, short, byte, ushort
  public static unsafe Vector<T> Match(Vector<T> mask, Vector<T> left, Vector<T> right); // MATCH

  /// T: sbyte, short, byte, ushort
  public static unsafe Vector<T> NoMatch(Vector<T> mask, Vector<T> left, Vector<T> right); // NMATCH

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[Copilot]

Pull request overview

Adds initial support for the Arm64 SVE2 Match / NoMatch intrinsics (and corresponding tests) to the runtime/JIT and the HWIntrinsic test generator.

Changes:

• Introduces new SVE2 intrinsics Match and NoMatch for byte/sbyte/short/ushort.
• Extends SVE2 test generation to cover the new intrinsics.
• Adds managed test helper implementations for expected results.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/tests/JIT/HardwareIntrinsics/Arm/Shared/Helpers.cs	Adds Match/NoMatch helper logic for expected-value computation (but this file is generated).
src/tests/Common/GenerateHWIntrinsicTests/Arm/Sve2Tests.cs	Adds generator entries to produce tests for Match/NoMatch.
src/libraries/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.cs	Adds the public ref declarations for Match/NoMatch.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Arm/Sve2.cs	Adds the SVE2 API surface for Match/NoMatch.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Arm/Sve2.PlatformNotSupported.cs	Adds PNSE stubs for Match/NoMatch when SVE2 isn’t supported.
src/coreclr/jit/hwintrinsiclistarm64sve.h	Registers the new SVE2 intrinsics with the JIT intrinsic table.