[lld] [WIP] wasm-ld: Implement function pointer alignment (PR #105532)

[Sam Clegg via llvm-commits]

sbc100 wrote:

Since we are implementing this as a linker flag and not a compiler flag I don't think there any need to mimik the existing compiler flags.   I think simply `--function-alignment=X` is fine, or maybe even `--function-pointer-alignment=X` (since this only effects function pointer and not functions.

I don't think need a separate padding flag since we already have `--table-base`.

https://github.com/llvm/llvm-project/pull/105532