[index] Add a caller relation for a call reference.

llvm-svn: 262207
diff --git a/clang/lib/Index/IndexSymbol.cpp b/clang/lib/Index/IndexSymbol.cpp
index 96da7a7..39812c4 100644
--- a/clang/lib/Index/IndexSymbol.cpp
+++ b/clang/lib/Index/IndexSymbol.cpp
@@ -206,6 +206,7 @@
   APPLY_FOR_ROLE(RelationBaseOf);
   APPLY_FOR_ROLE(RelationOverrideOf);
   APPLY_FOR_ROLE(RelationReceivedBy);
+  APPLY_FOR_ROLE(RelationCalledBy);
 
 #undef APPLY_FOR_ROLE
 }
@@ -231,6 +232,7 @@
     case SymbolRole::RelationBaseOf: OS << "RelBase"; break;
     case SymbolRole::RelationOverrideOf: OS << "RelOver"; break;
     case SymbolRole::RelationReceivedBy: OS << "RelRec"; break;
+    case SymbolRole::RelationCalledBy: OS << "RelCall"; break;
     }
   });
 }