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/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 5de43bb..8339bdd 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -3617,7 +3617,7 @@
   // cast; don't do it if we're ignoring -Wcast_align (as is the default).
   if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align,
                                           TRange.getBegin())
-        == Diagnostic::Ignored)
+        == DiagnosticsEngine::Ignored)
     return;
 
   // Ignore dependent types.