[clang] [Sema] Mark alias/ifunc targets used and consider mangled names (PR #87130)

[Nick Desaulniers via cfe-commits]

================
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -triple %itanium_abi_triple -Wunused -x c -verify %s
----------------
nickdesaulniers wrote:

> but git does not preserve file move history...

Sure it does; isn't that the point of the `--follow` flag to `git log <file>`?

https://github.com/llvm/llvm-project/pull/87130