Revert of [es6] Fix scoping for default parameters in arrow functions

src/pattern-rewriter.cc

Index: src/pattern-rewriter.cc
diff --git a/src/pattern-rewriter.cc b/src/pattern-rewriter.cc
index ce0689404e0526d089aa402e5d68b10fae064181..1a85ff77e4a54b8ee494cd04ae6a9ab02df63bce 100644
--- a/src/pattern-rewriter.cc
+++ b/src/pattern-rewriter.cc
@@ -4,7 +4,6 @@
 
 #include "src/ast.h"
 #include "src/messages.h"
-#include "src/parameter-initializer-rewriter.h"
 #include "src/parser.h"
 
 namespace v8 {
@@ -360,16 +359,8 @@
       Token::EQ_STRICT, factory()->NewVariableProxy(temp),
       factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
       RelocInfo::kNoPosition);
-  Expression* initializer = node->value();
-  if (descriptor_->declaration_kind == DeclarationDescriptor::PARAMETER &&
-      descriptor_->scope->is_arrow_scope()) {
-    // TODO(adamk): Only call this if necessary.
-    RewriteParameterInitializerScope(
-        descriptor_->parser->stack_limit(), initializer,
-        descriptor_->scope->outer_scope(), descriptor_->scope);
-  }
   Expression* value = factory()->NewConditional(
-      is_undefined, initializer, factory()->NewVariableProxy(temp),
+      is_undefined, node->value(), factory()->NewVariableProxy(temp),
       RelocInfo::kNoPosition);
   RecurseIntoSubpattern(node->target(), value);
 }