Add PerfMap OS/arch constants for wasm and wasi targets

[pavelsavara]

Summary

Crossgen2 ReadyToRun compilation for browser-wasm and wasi-wasm targets threw System.NotImplementedException from PerfMapWriter.TranslateTargetDetailsToPerfmapConstants when PublishReadyToRunPerfmapFormatVersion was set. PerfMapOSToken had no Browser/Wasi members and PerfMapArchitectureToken had no Wasm member, so the switch expressions fell through to their throwing default arms.

Observed stack:

System.NotImplementedException: Browser
   at ILCompiler.Diagnostics.PerfMapWriter.TranslateTargetDetailsToPerfmapConstants(TargetDetails details) in PerfMapWriter.cs:line 121
   at ILCompiler.Diagnostics.PerfMapWriter.PerfMapV1SignatureHelper(...)
   at ILCompiler.DependencyAnalysis.ReadyToRun.PerfMapDebugDirectoryEntryNode.GetData(...)
   at ILCompiler.ReadyToRunCodegenCompilation.Compile(String outputFile)

Changes

• Add Browser = 8 and Wasi = 9 to PerfMapOSToken, and Wasm = 7 to PerfMapArchitectureToken (appended after the highest existing value to preserve the numeric contract consumed by symbol-upload / PerfView tooling).
• Map TargetOS.Browser/TargetOS.Wasi and TargetArchitecture.Wasm32 in the PerfMapWriter switches.
• Update docs/design/coreclr/botr/r2r-perfmap-format.md to match, also filling in the already-shipped OpenBSD/RiscV64/LoongArch64 rows that were missing from the doc.

Validation

• Built ILCompiler.Diagnostics (Release) — clean.
• Full Release build with PublishReadyToRunPerfmapFormatVersion = 1 — the CreateReadyToRunImages target now runs with 0 errors where it previously threw.

Note

This PR description and the code changes were generated with the assistance of GitHub Copilot.

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[Copilot]

Pull request overview

Adds missing PerfMap v1 target OS/architecture tokens and wiring so Crossgen2 ReadyToRun perfmap emission can support WebAssembly targets (Browser/WASI) without falling into the “unknown target” throwing paths. Also updates the design doc to reflect the expanded token sets.

Changes:

• Extend PerfMapOSToken with Browser/Wasi and PerfMapArchitectureToken with Wasm.
• Map TargetOS.Browser/TargetOS.Wasi and TargetArchitecture.Wasm32 to the new tokens in PerfMapWriter.
• Update r2r-perfmap-format.md to include the current token tables.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/coreclr/tools/aot/ILCompiler.Diagnostics/ReadyToRunDiagnosticsConstants.cs	Adds new perfmap OS/arch enum values used as the on-disk perfmap contract.
src/coreclr/tools/aot/ILCompiler.Diagnostics/PerfMapWriter.cs	Extends target-to-token translation to cover Browser/WASI and Wasm32.
docs/design/coreclr/botr/r2r-perfmap-format.md	Documents the updated token values for perfmap v1 headers.