Added operator overloading for unary operators, post-increment, and
post-decrement, including support for generating all of the built-in
operator candidates for these operators. 

C++ and C have different rules for the arguments to the builtin unary
'+' and '-'. Implemented both variants in Sema::ActOnUnaryOp.

In C++, pre-increment and pre-decrement return lvalues. Update
Expr::isLvalue accordingly.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59638 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index 49b8180..221ad90 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -386,7 +386,8 @@
         }
         
         // Add the __extension__ node to the AST.
-        Res = Actions.ActOnUnaryOp(ExtLoc, tok::kw___extension__, Res.Val);
+        Res = Actions.ActOnUnaryOp(CurScope, ExtLoc, tok::kw___extension__, 
+                                   Res.Val);
         if (Res.isInvalid)
           continue;