[llvm] [MergeFunc] Remove discardables function before writing alias or thunk. (PR #128865)

[Florian Hahn via llvm-commits]

================
@@ -875,9 +876,14 @@ void MergeFunctions::writeAlias(Function *F, Function *G) {
   ++NumAliasesWritten;
 }
 
-// Replace G with an alias to F if possible, or a thunk to F if
-// profitable. Returns false if neither is the case.
-bool MergeFunctions::writeThunkOrAlias(Function *F, Function *G) {
+// If needed, replace G with an alias to F if possible, or a thunk to F if
+// profitable. Returns false if neither is the case. If \p G is not needed (e.g.
+// it is discardable and linkonce_odr), \p G is removed directly.
----------------
fhahn wrote:

`linkonce_odr` was meant as an example, but I changed it to `i.e.` instead of `e.g.` and update to discardable and unused, thanks

https://github.com/llvm/llvm-project/pull/128865