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

[Teresa Johnson via llvm-commits]

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@@ -43,14 +43,8 @@ define linkonce i32 @funA(i32 %x, i32 %y) {
 ; CHECK-NEXT:    ret i32 [[SUM3]]
 ;
 ;
-; CHECK-LABEL: define linkonce i32 @funC(
-; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) {
-; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @[[GLOB0:[0-9]+]](i32 [[TMP0]], i32 [[TMP1]])
-; CHECK-NEXT:    ret i32 [[TMP3]]
-;
-;
 ; CHECK-LABEL: define linkonce i32 @funB(
 ; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) {
-; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @[[GLOB0]](i32 [[TMP0]], i32 [[TMP1]])
+; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @[[GLOB0:[0-9]+]](i32 [[TMP0]], i32 [[TMP1]])
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teresajohnson wrote:

> Yep, the thunk that we introduce may also end up dead and could be cleaned up. I can also look into that separately?

Is this in reference to GLOB0? I'm confused then - what does GLOB0 end up equaling if not the introduced @0?

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