Fix legacy const for-of/in destructuring

src/pattern-rewriter.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/ast.h"
 #include "src/messages.h"
 #include "src/parser.h"
 
 namespace v8 {
 
@@ skipping 157 matching lines @@
       } else {
         initialize = NULL;
       }
     }
 
     if (initialize != NULL) {
       block_->statements()->Add(
           factory()->NewExpressionStatement(initialize, RelocInfo::kNoPosition),
           zone());
     }
-  } else if (value != nullptr && (descriptor_->needs_init ||
+  } else if (value != nullptr && (descriptor_->mode == CONST_LEGACY ||

[adamk, 2015/10/05 22:17:51]

I like this better, too; the old code is very odd looking.

                                   IsLexicalVariableMode(descriptor_->mode))) {
     // Constant initializations always assign to the declared constant which
     // is always at the function scope level. This is only relevant for
     // dynamically looked-up variables and constants (the
     // start context for constant lookups is always the function context,
     // while it is the top context for var declared variables). Sigh...
     // For 'let' and 'const' declared variables in harmony mode the
     // initialization also always assigns to the declared variable.
     DCHECK_NOT_NULL(proxy);
     DCHECK_NOT_NULL(proxy->var());
@@ skipping 222 matching lines @@
 NOT_A_PATTERN(TryFinallyStatement)
 NOT_A_PATTERN(UnaryOperation)
 NOT_A_PATTERN(VariableDeclaration)
 NOT_A_PATTERN(WhileStatement)
 NOT_A_PATTERN(WithStatement)
 NOT_A_PATTERN(Yield)
 
 #undef NOT_A_PATTERN
 }  // namespace internal
 }  // namespace v8