[lld] [llvm] [WebAssembly] Allow strings for import modules and names in asm (PR #182896)

[Sy Brand via llvm-commits]

TartanLlama wrote:

I've backed out the dollar change from this PR.

It looks like, due to how `MC/MCParser/AsmLexer.cpp` is written, the assembler already supports `$` and `?` in the middle of identifiers, just not at the start. Whether this is the desired behaviour or supported by `wasm-ld` is probably a question for another PR. For now, I've reflected this in the characters I check for when quoting, and I've added tests to ensure that my modifications don't change the status quo. 

https://github.com/llvm/llvm-project/pull/182896