Rename Diagnostic to DiagnosticsEngine as per issue 5397


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140478 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index cfe9374..5a603b6 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -690,7 +690,8 @@
 
   // If the use of an extension results in an error diagnostic, extensions are
   // effectively unavailable, so just return false here.
-  if (PP.getDiagnostics().getExtensionHandlingBehavior()==Diagnostic::Ext_Error)
+  if (PP.getDiagnostics().getExtensionHandlingBehavior() ==
+      DiagnosticsEngine::Ext_Error)
     return false;
 
   const LangOptions &LangOpts = PP.getLangOptions();