Don't add a SourceLocation for 'self' if it does not actually appears in the source code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76295 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 1304558..35c0ddb 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -902,7 +902,8 @@
           // FIXME: This should use a new expr for a direct reference, don't
           // turn this into Self->ivar, just return a BareIVarExpr or something.
           IdentifierInfo &II = Context.Idents.get("self");
-          OwningExprResult SelfExpr = ActOnIdentifierExpr(S, Loc, II, false);
+          OwningExprResult SelfExpr = ActOnIdentifierExpr(S, SourceLocation(),
+                                                          II, false);
           MarkDeclarationReferenced(Loc, IV);
           return Owned(new (Context) 
                        ObjCIvarRefExpr(IV, IV->getType(), Loc,