Code Coverage Support

[kateinoigakukun]

• Ship ./compiler-rt/profile in the SDK [wasm][build] Enable building compiler-rt/lib/profile  swiftlang/swift#77020
  • [Coverage][WebAssembly] Add initial support for WebAssembly/WASI llvm/llvm-project#111332
• Add -profile-generate driver option support support in swift-driver and pass libcompiler_rt.profile.a to the clang linker: https://github.com/swiftlang/swift-driver/blob/0155ae03cd329ca33b13b65ec50dd42a43a840ea/Sources/SwiftDriver/Jobs/WebAssemblyToolchain%2BLinkerSupport.swift#L161 Unlock -profile-generate for WebAssembly targets swiftlang/swift-driver#1712

$ swift build --swift-sdk DEVELOPMENT-SNAPSHOT-2024-08-11-a-wasm32-unknown-wasi --build-tests  --enable-code-coverage
Building for debugging...
error: profiling is unsupported for target 'wasm32-unknown-wasi'
[17/18] Linking ExamplePackageTests.wasm

• Place and load coverage metadata on/from custom sections instead of data segments