[clang] [clang][PowerPC] Add flag to enable compatibility with GNU for complex arguments (PR #77732)

[Amy Kwan via cfe-commits]

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@@ -223,6 +223,8 @@ CODEGENOPT(MCDCCoverage , 1, 0) ///< Enable MC/DC code coverage criteria.
 
   /// If -fpcc-struct-return or -freg-struct-return is specified.
 ENUM_CODEGENOPT(StructReturnConvention, StructReturnConventionKind, 2, SRCK_Default)
+  /// If -fcomplex-ppc-gnu-abi for ppc32
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amy-kwan wrote:

```suggestion
  /// If -fcomplex-ppc-gnu-abi is specified on ppc32.
```
This sentence might read a bit better.

https://github.com/llvm/llvm-project/pull/77732