[clang] [compiler-rt] [llvm] [AIX] Implement the ifunc attribute. (PR #153049)

[Sean Fertile via llvm-commits]

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@@ -2391,7 +2391,8 @@ MCSymbol *
 TargetLoweringObjectFileXCOFF::getTargetSymbol(const GlobalValue *GV,
                                                const TargetMachine &TM) const {
   // We always use a qualname symbol for a GV that represents
-  // a declaration, a function descriptor, or a common symbol.
+  // a declaration, a function descriptor, or a common symbol. An IFunc is
+  // lowered as a function, so it has an entry point and a descriptor.
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mandlebug wrote:

Really minor nit: 
```suggestion
  // lowered as a special trampoline function which has an entry point and a descriptor.
```

https://github.com/llvm/llvm-project/pull/153049