[clang] [WebAssembly] fix: respect -Wl, --no-demangle option (PR #213878)

[Martin Liška via cfe-commits]

marxin wrote:

If I read it correctly, it must be some historical relict of the Clang driver:

clang/include/clang/Options/Options.td:
```
// Special internal option to handle -Xlinker --no-demangle.
def Z_Xlinker__no_demangle : Flag<["-"], "Z-Xlinker-no-demangle">,
    Flags<[Unsupported, NoArgumentUnused]>;
```

Note it's the only `wasm-ld` option that has the special Driver option (of type `OPT_Z_Xlinker_*`). That said, it explains why other options passed as `-Wl` are properly passed to the linker.

https://github.com/llvm/llvm-project/pull/213878