[lld] [LLD][COFF] Clarify EC vs. native symbols in diagnostics on ARM64X (PR #130857)

[Martin Storsjö via llvm-commits]

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

Mostly LGTM, but there seemed to be some leftover commented out code, that probably should be properly removed (or kept?), but commented out feels wrong.

I agree with the design decision to only print this when we have two separate namespaces. You mentioned that MS link.exe prints the EC disambiguation even for plain arm64ec links, but I presume it only prints the "arm64 native symbol" when linking a hybrid image?

https://github.com/llvm/llvm-project/pull/130857