bcgit

Use when the user is writing, modifying, reviewing, or verifying hardware-intrinsics code in bc-csharp — i.e. anything under crypto/src/runtime/intrinsics/, any *_X86.cs file, or any other code that uses System.Runtime.Intrinsics. Covers the project rule that ISA detection must go through the Org.BouncyCastle.Runtime.Intrinsics wrappers (not direct System.Runtime.Intrinsics.X86.*.IsSupported checks), commands to re-run tests with specific instruction sets disabled via DOTNET_Enable*/COMPlus_Enable* env vars so scalar and lower-ISA fallback codepaths get exercised, and the planned trajectory toward a limited set of supported ISA profiles.