[llvm] [PowerPC][AIX] Emit PowerPC version for XCOFF (PR #113214)

[Kai Nacke via llvm-commits]

================
@@ -423,7 +427,8 @@ class PPCTargetXCOFFStreamer : public PPCTargetStreamer {
   }
 
   void emitMachine(StringRef CPU) override {
-    llvm_unreachable("Machine pseudo-ops are invalid for XCOFF.");
+    MCXCOFFStreamer &XCOFFStreamer = static_cast<MCXCOFFStreamer &>(Streamer);
+    XCOFFStreamer.getAssembler().getWriter().setCPU(CPU);
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redstar wrote:

With the other changes this would become:
```suggestion
    static_cast<XCOFFObjectWriter>(Streamer.getAssembler().getWriter()).setCPU(CPU);
```

https://github.com/llvm/llvm-project/pull/113214