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

[Anutosh Bhat via llvm-commits]

anutosh491 wrote:

Squashed the commits into 2 meaningful commits. The CI on the commit before the squash was passing too.

I think this would now be ready from my side.

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