[clang] [clang] Implement __attribute__((format_matches)) (PR #116708)

[Erich Keane via cfe-commits]

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@@ -3738,6 +3738,103 @@ behavior of the program is undefined.
   }];
 }
 
+def FormatMatchesDocs : Documentation {
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erichkeane wrote:

I'm hopeful someone comes along and does a better 'english/documentation-quality' review of this.  I don't have the mental acuity at the moment.

https://github.com/llvm/llvm-project/pull/116708