[llvm] [PowerPC] add PowerPC path for PR labeler (PR #82200)

[Fangrui Song via llvm-commits]

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@@ -822,6 +822,23 @@ backend:X86:
   - llvm/lib/TargetParser/X86*
   - llvm/utils/TableGen/X86*
 
+backend:PowerPC:
+  - llvm/include/llvm/IR/IntrinsicsPowerPC.td
+  - llvm/lib/Target/PowerPC/**
+  - llvm/test/CodeGen/PowerPC/**
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MaskRay wrote:

I favor simple `llvm/test/**/PowerPC/**` and `llvm/test/**/XCOFF/**`

https://github.com/llvm/llvm-project/pull/82200