[lld] [llvm] [LTO] [LLD] Don't alias the __imp_func and func symbol resolutions (PR #71376)

[Fangrui Song via llvm-commits]

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

> The only level that knows of the potential relationship between the `__imp_` prefixed and unprefixed symbol, across regular and bitcode object files, is LLD itself.

Agreed.

> Previously, the aliasing of global resolutions at the LTO level would trigger a failed assert with "Multiple prevailing defs are not allowed" for this case, as both importedFunc and __imp_importedFunc could be prevailing. Add a case to the existing LLD test case lto-imp-prefix.ll to test this as well.

Confirmed.

The LLD fix is indeed better than https://reviews.llvm.org/D49138 . Whether the unprefixed is external does not matter now.


https://github.com/llvm/llvm-project/pull/71376