[arcmt] When capturing ARC errors, have a sanity check to make sure

the diagnostic has a valid location.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170040 91177308-0d34-0410-b5e6-96231b3b80d8

Author: akyrtzi

lib/ARCMigrate/ARCMT.cpp

@@ -130,7 +130,8 @@ class CaptureDiagnosticConsumer : public DiagnosticConsumer {
                                 const Diagnostic &Info) {
     if (DiagnosticIDs::isARCDiagnostic(Info.getID()) ||
         level >= DiagnosticsEngine::Error || level == DiagnosticsEngine::Note) {
-      CapturedDiags.push_back(StoredDiagnostic(level, Info));
+      if (Info.getLocation().isValid())
+        CapturedDiags.push_back(StoredDiagnostic(level, Info));
       return;
     }