Make PTH warnings actual warnings instead of 'notes'.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65071 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index ac510af..b0a610d 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -584,7 +584,7 @@
 static void InvalidPTH(Diagnostic *Diags, const char* Msg = 0) {
   if (!Diags) return;  
   if (!Msg) Msg = "Invalid or corrupted PTH file";
-  unsigned DiagID = Diags->getCustomDiagID(Diagnostic::Note, Msg);
+  unsigned DiagID = Diags->getCustomDiagID(Diagnostic::Warning, Msg);
   Diags->Report(FullSourceLoc(), DiagID);
 }