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/Parse/RAIIObjectsForParser.h b/lib/Parse/RAIIObjectsForParser.h
index 3765f92..ef17aee 100644
--- a/lib/Parse/RAIIObjectsForParser.h
+++ b/lib/Parse/RAIIObjectsForParser.h
@@ -30,9 +30,9 @@
   class ExtensionRAIIObject {
     void operator=(const ExtensionRAIIObject &);     // DO NOT IMPLEMENT
     ExtensionRAIIObject(const ExtensionRAIIObject&); // DO NOT IMPLEMENT
-    Diagnostic &Diags;
+    DiagnosticsEngine &Diags;
   public:
-    ExtensionRAIIObject(Diagnostic &diags) : Diags(diags) {
+    ExtensionRAIIObject(DiagnosticsEngine &diags) : Diags(diags) {
       Diags.IncrementAllExtensionsSilenced();
     }