[crankshaft] Remove the global arguments object from the HGraph.

This was actually only necessary for dealing with %_Arguments and
%_ArgumentsLength in Crankshaft, which have been removed recently,
so there's no need to keep this piece of awesomeness around any
longer.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1695193003

Cr-Commit-Position: refs/heads/master@{#34015}

src/crankshaft/hydrogen.cc

@@ -4664,12 +4664,11 @@ void HOptimizedGraphBuilder::SetUpScope(Scope* scope) {
   }
 
   AddInstruction(arguments_object);
-  graph()->SetArgumentsObject(arguments_object);
 
   // Handle the arguments and arguments shadow variables specially (they do
   // not have declarations).
   if (scope->arguments() != NULL) {
-    environment()->Bind(scope->arguments(), graph()->GetArgumentsObject());
+    environment()->Bind(scope->arguments(), arguments_object);
   }
 
   int rest_index;
@@ -7856,7 +7855,7 @@ bool HOptimizedGraphBuilder::TryArgumentsAccess(Property* expr) {
       result = New<HConstant>(argument_count);
     }
   } else {
-    Push(graph()->GetArgumentsObject());
+    CHECK_ALIVE_OR_RETURN(VisitForValue(expr->obj(), ARGUMENTS_ALLOWED), true);
     CHECK_ALIVE_OR_RETURN(VisitForValue(expr->key()), true);
     HValue* key = Pop();
     Drop(1);  // Arguments object.

src/crankshaft/hydrogen.h

@@ -346,13 +346,6 @@ class HGraph final : public ZoneObject {
   bool IsStandardConstant(HConstant* constant);
 
   HBasicBlock* CreateBasicBlock();
-  HArgumentsObject* GetArgumentsObject() const {
-    return arguments_object_.get();
-  }
-
-  void SetArgumentsObject(HArgumentsObject* object) {
-    arguments_object_.set(object);
-  }
 
   int GetMaximumValueID() const { return values_.length(); }
   int GetNextBlockID() { return next_block_id_++; }
@@ -482,7 +475,6 @@ class HGraph final : public ZoneObject {
   SetOncePointer<HConstant> constant_the_hole_;
   SetOncePointer<HConstant> constant_null_;
   SetOncePointer<HConstant> constant_invalid_context_;
-  SetOncePointer<HArgumentsObject> arguments_object_;
 
   HOsrBuilder* osr_;