[clang] [llvm] [WebAssembly] Add gc target feature to addBleedingEdgeFeatures (PR #151107)

[Heejin Ahn via llvm-commits]

aheejin wrote:

> https://github.com/llvm/llvm-project/blob/main/clang/test/Driver/wasm-features.c needs to be updated too. For example, this is `fp16`:
> 
> https://github.com/llvm/llvm-project/blob/052b836d2384c8a583ae5f945dcdcfba2004bbb0/clang/test/Driver/wasm-features.c#L38-L42

I don't this this is updated?

https://github.com/llvm/llvm-project/pull/151107