[llvm] [WebAssemblyLowerEmscriptenEHSjLj] Don't assign import names to generated function declarations (PR #71599)

[Heejin Ahn via llvm-commits]

aheejin wrote:

> The reason this now works is that we pass a list of known JS function to the linker, which tells the linker its OK to import them. So we no longer need to tell the linker in to import them using this method.

Not necessarily related to this PR, but can you point where in emscripten we do that, to help my understanding of how they work? Thanks!

https://github.com/llvm/llvm-project/pull/71599