From Vassil Vassilev: enable Sema to deal with multiple ExternalSemaSources.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166208 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 20fa279..489e0a6 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -5564,7 +5564,7 @@
 
 void ASTReader::InitializeSema(Sema &S) {
   SemaObj = &S;
-  S.ExternalSource = this;
+  S.addExternalSource(this);
 
   // Makes sure any declarations that were deserialized "too early"
   // still get added to the identifier's declaration chains.