[es6] implement destructuring assignment

src/typing-asm.cc

 // Copyright 2015 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/typing-asm.h"
 
 #include "src/ast.h"
 #include "src/codegen.h"
@@ skipping 482 matching lines @@
     FAIL(expr, "illegal literal");
   }
 }
 
 
 void AsmTyper::VisitRegExpLiteral(RegExpLiteral* expr) {
   FAIL(expr, "regular expression encountered");
 }
 
 
+void AsmTyper::VisitAssignmentPattern(AssignmentPattern* expr) {
+  Visit(expr->expression());
+}
+
+
 void AsmTyper::VisitObjectLiteral(ObjectLiteral* expr) {
   if (in_function_) {
     FAIL(expr, "object literal in function");
   }
   // Allowed for asm module's export declaration.
   ZoneList<ObjectLiteralProperty*>* props = expr->properties();
   for (int i = 0; i < props->length(); ++i) {
     ObjectLiteralProperty* prop = props->at(i);
     RECURSE(VisitWithExpectation(prop->value(), Type::Any(zone()),
                                  "object property expected to be a function"));
@@ skipping 611 matching lines @@
     computed_type_->Print();
     PrintF("Expected type: ");
     expected_type_->Print();
 #endif
     FAIL(expr, msg);
   }
   expected_type_ = save;
 }
 }  // namespace internal
 }  // namespace v8