[es6] Check declaration conflicts between non-simple parameters and the function body

src/parser.cc

 // Copyright 2012 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/api.h"
 #include "src/ast.h"
 #include "src/ast-literal-reindexer.h"
 #include "src/bailout-reason.h"
@@ skipping 4425 matching lines @@
   if (!is_simple_parameter_list) {
     DCHECK_NOT_NULL(inner_scope);
     DCHECK_EQ(body, inner_block->statements());
     scope_->SetLanguageMode(inner_scope->language_mode());
     Block* init_block =
         BuildParameterInitializationBlock(formal_parameters, CHECK_OK);
     DCHECK_NOT_NULL(init_block);
 
     inner_scope->set_end_position(scanner()->location().end_pos);
     inner_scope = inner_scope->FinalizeBlockScope();
+    if (inner_scope != nullptr) {
+      CheckConflictingVarDeclarations(inner_scope, CHECK_OK);
+    }
 
     result->Add(init_block, zone());
     result->Add(inner_block, zone());
   }
 
   return result;
 }
 
 
 PreParser::PreParseResult Parser::ParseLazyFunctionBodyWithPreParser(
@@ skipping 1535 matching lines @@
 Expression* Parser::SpreadCallNew(Expression* function,
                                   ZoneList<v8::internal::Expression*>* args,
                                   int pos) {
   args->InsertAt(0, function, zone());
 
   return factory()->NewCallRuntime(
       ast_value_factory()->reflect_construct_string(), NULL, args, pos);
 }
 }  // namespace internal
 }  // namespace v8