[clang] [Format] Fix isStartOfName to recognize attributes (PR #76804)

[Björn Schäpers via cfe-commits]

================
@@ -1698,8 +1698,6 @@ FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
           /*BasedOnStyle=*/"google",
       },
   };
-  GoogleStyle.AttributeMacros.push_back("GUARDED_BY");
----------------
HazardyKnusperkeks wrote:

Even if that would not be needed anymore to achieve the expected formatting, these are AttributeMacros, and should be declared as such.

https://github.com/llvm/llvm-project/pull/76804