[clang] [llvm] Add __builtin_wasm_js_catch (PR #153767)

[Hood Chatham via cfe-commits]

hoodmane wrote:

@efriedma-quic that sounds good to me, I'll have to look into how `__try`/ `__catch` work on windows. I was just trying to copy the semantics of a C API that I knew about, so setjmp/longjmp. But a more direct API would probably also have a simpler implementation.

https://github.com/llvm/llvm-project/pull/153767