fix quick OOM in FormatDiagnostic

Author: igelbox

clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp

@@ -380,7 +380,6 @@ void ClangTidyDiagnosticConsumer::HandleDiagnostic(
     ++Context.Stats.ErrorsIgnoredNOLINT;
     // Ignored a warning, should ignore related notes as well
     LastErrorWasIgnored = true;
-    Context.DiagEngine->Clear();
     for (const auto &Error : SuppressionErrors)
       Context.diag(Error);
     return;
@@ -457,7 +456,6 @@ void ClangTidyDiagnosticConsumer::HandleDiagnostic(
   if (Info.hasSourceManager())
     checkFilters(Info.getLocation(), Info.getSourceManager());
 
-  Context.DiagEngine->Clear();
   for (const auto &Error : SuppressionErrors)
     Context.diag(Error);
 }