Make invalid LHSs that are calls late errors

src/variables.h

Index: src/variables.h
diff --git a/src/variables.h b/src/variables.h
index 401d04446379784708a41c32c2b575050b59a54e..51b7362d4620c48d6a3873c2af25eb822282c3de 100644
--- a/src/variables.h
+++ b/src/variables.h
@@ -77,7 +77,7 @@ class Variable: public ZoneObject {
   Variable(Scope* scope,
            Handle<String> name,
            VariableMode mode,
-           bool is_valid_lhs,
+           bool is_valid_ref,
            Kind kind,
            InitializationFlag initialization_flag,
            Interface* interface = Interface::NewValue());
@@ -85,7 +85,7 @@ class Variable: public ZoneObject {
   // Printing support
   static const char* Mode2String(VariableMode mode);
 
-  bool IsValidLeftHandSide() { return is_valid_LHS_; }
+  bool IsValidReference() { return is_valid_ref_; }
 
   // The source code for an eval() call may refer to a variable that is
   // in an outer scope about which we don't know anything (it may not
@@ -172,8 +172,8 @@ class Variable: public ZoneObject {
   // binding scope (exclusive).
   Variable* local_if_not_shadowed_;
 
-  // Valid as a LHS? (const and this are not valid LHS, for example)
-  bool is_valid_LHS_;
+  // Valid as a reference? (const and this are not valid, for example)
+  bool is_valid_ref_;
 
   // Usage info.
   bool force_context_allocation_;  // set by variable resolver