[wasm] Include `_CFIsMainThread` for WASI platform#5292

kateinoigakukun wants to merge 1 commit intoswiftlang:mainswiftlang/swift-corelibs-foundation:mainfrom

kateinoigakukun:pr-3546affe655c5dd7c2e0c1d4b02671058aaff35dkateinoigakukun/swift-corelibs-foundation:pr-3546affe655c5dd7c2e0c1d4b02671058aaff35dCopy head branch name to clipboard