Distinguish the various kinds of AST file loading failures:
file corruption, compiler version mismatch, target/language
configuration mismatch, out-of-date AST file. No functionality change
yet.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166446 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ChainedIncludesSource.cpp b/lib/Frontend/ChainedIncludesSource.cpp
index 5f7ff74..bfe0693 100644
--- a/lib/Frontend/ChainedIncludesSource.cpp
+++ b/lib/Frontend/ChainedIncludesSource.cpp
@@ -46,7 +46,10 @@
     return Reader.take();
 
   case ASTReader::Failure:
-  case ASTReader::IgnorePCH:
+  case ASTReader::OutOfDate:
+  case ASTReader::VersionMismatch:
+  case ASTReader::ConfigurationMismatch:
+  case ASTReader::HadErrors:
     break;
   }
   return 0;