[clang] [llvm] [AIX] Lower intrinsic __builtin_cpu_is into AIX platform-specific code. (PR #80069)

[Amy Kwan via llvm-commits]

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@@ -16542,12 +16542,62 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
 
   Intrinsic::ID ID = Intrinsic::not_intrinsic;
 
+#include "llvm/TargetParser/PPCTargetParser.def"
+  // This lambda function converts builtin_cpu_is() into directly
+  // returning true or false, or it gets and checks the information from the
+  // kernel variable _system_configuration fromr the AIX OS.
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amy-kwan wrote:

```suggestion
  // kernel variable _system_configuration from the AIX OS.
```

https://github.com/llvm/llvm-project/pull/80069