harmony-scoping: make assignment to 'const' a late error.

src/runtime/runtime-scopes.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/arguments.h"
 #include "src/frames-inl.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/scopeinfo.h"
 #include "src/scopes.h"
 
 namespace v8 {
 namespace internal {
 
 static Object* ThrowRedeclarationError(Isolate* isolate, Handle<String> name) {
   HandleScope scope(isolate);
   Handle<Object> args[1] = {name};
   THROW_NEW_ERROR_RETURN_FAILURE(
       isolate, NewTypeError("var_redeclaration", HandleVector(args, 1)));
 }
 
 
+RUNTIME_FUNCTION(Runtime_ThrowConstAssignError) {
+  HandleScope scope(isolate);
+  THROW_NEW_ERROR_RETURN_FAILURE(
+      isolate,
+      NewTypeError("harmony_const_assign", HandleVector<Object>(NULL, 0)));
+}
+
+
 // May throw a RedeclarationError.
 static Object* DeclareGlobals(Isolate* isolate, Handle<GlobalObject> global,
                               Handle<String> name, Handle<Object> value,
                               PropertyAttributes attr, bool is_var,
                               bool is_const, bool is_function) {
   Handle<ScriptContextTable> script_contexts(
       global->native_context()->script_context_table());
   ScriptContextTable::LookupResult lookup;
   if (ScriptContextTable::Lookup(script_contexts, name, &lookup) &&
       IsLexicalVariableMode(lookup.mode)) {
@@ skipping 1034 matching lines @@
   return Smi::FromInt(frame->GetArgumentsLength());
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_Arguments) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_GetArgumentsProperty(args, isolate);
 }
 }
 }  // namespace v8::internal