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

lib/Lex/PTHLexer.cpp

@@ -584,7 +584,7 @@ PTHManager::~PTHManager() {
 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);
 }