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

[Sam Clegg via llvm-commits]

sbc100 wrote:

Looks like maybe you need to run `git clang-format origin/main` to update the formatting of the changed lines.

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