[llvm] [WebAssembly] Add symbol information for shared libraries (PR #75238)

[Sam Clegg via llvm-commits]

sbc100 wrote:

> ah yeah, isRelocatableObject might be good enough for that. Maybe the "ideal" behavior for an nm-like use case would be to construct a symbol table that synthesizes information from both the export section if possible (these would show external symbol types like "T" and others you have here) and the name section if possible (for internal symbols like "t")... presumably the export names should override the name section names? I guess that would work OK for the linker since it's only concerned with exported and imported symbols?

I see, yes, for llvm-nm we might want to do more here, but for wasm-ld we only really care about exports (and maybe later about imports). 

Presumably was can consider extending support for the name section as a followup?

https://github.com/llvm/llvm-project/pull/75238