[lld] [wasm-ld] Refactor WasmSym from static globals to per-link context (PR #134970)

[Anutosh Bhat via llvm-commits]

anutosh491 wrote:

Thanks a lot @sbc100 for the quick reviews here 
Much appreciated :)

I have made the changes related to git formatting in the latest commit .

https://github.com/llvm/llvm-project/pull/134970