[clang] [llvm] [WebAssembly,clang] Add __builtin_wasm_test_function_pointer_signature (PR #150201)

[Hood Chatham via llvm-commits]

hoodmane wrote:

@dschuff would appreciate it if you could merge assuming you have no further comments and the addition of the GC feature looks okay.

https://github.com/llvm/llvm-project/pull/150201