Revert of Parse arrow functions at proper precedence level

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
 #include "src/ast-numbering.h"
@@ skipping 11507 matching lines @@
     HIfContinuation continuation;
     BuildCompareNil(value, type, &continuation);
     return ast_context()->ReturnContinuation(&continuation, expr->id());
   }
 }
 
 
 void HOptimizedGraphBuilder::VisitSpread(Spread* expr) { UNREACHABLE(); }
 
 
-void HOptimizedGraphBuilder::VisitEmptyParentheses(EmptyParentheses* expr) {
-  UNREACHABLE();
-}
-
-
 HInstruction* HOptimizedGraphBuilder::BuildThisFunction() {
   // If we share optimized code between different closures, the
   // this-function is not a constant, except inside an inlined body.
   if (function_state()->outer() != NULL) {
       return New<HConstant>(
           function_state()->compilation_info()->closure());
   } else {
       return New<HThisFunction>();
   }
 }
@@ skipping 1897 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8