[llvm] [WebAssembly][NFC] Add `call-wasm64.ll` to test subset of `call.ll` on Wasm64 (PR #188693)

[Sam Clegg via llvm-commits]

https://github.com/sbc100 approved this pull request.

I assume you looked into keeping this all in single file and using the `-DPPTR=i64` trick? (I guess you would also need to pass the target triple via the command line too, but I guess that is possible).

Otherwise LGTM

https://github.com/llvm/llvm-project/pull/188693