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

[Hood Chatham via cfe-commits]

hoodmane wrote:

@aheejin I will give a more detailed response about why this is necessary on Monday but the problem is that the `SuspendError` is generated inside the import wrapper:
https://github.com/v8/v8/blob/3c61391b55f06f880c7431c231f15014db34dfcc/src/wasm/wrappers.cc#L540-L568
So no JS code runs in between the call site to the wasm import and where the exception is raised. Thus, the error has to be caught in Wasm. See this issue:
https://github.com/WebAssembly/js-promise-integration/issues/29
particularly this comment:
https://github.com/WebAssembly/js-promise-integration/issues/29#issuecomment-3135713355


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