Extend lvalue evaluation in ExprConstant.cpp to handle CK_LValueBitCast (which is completely trivial).  PR8836.

llvm-svn: 141604
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 3da7449..c0f913d 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -481,7 +481,10 @@
       return false;
 
     case CK_NoOp:
+    case CK_LValueBitCast:
       return Visit(E->getSubExpr());
+
+    // FIXME: Support CK_DerivedToBase and friends.
     }
   }