Revert of Add script context with context-allocated "const this"

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/v8.h"
 
@@ skipping 10179 matching lines @@
     Add<HPushArguments>(obj, key, Add<HConstant>(function_language_mode()));
     // TODO(olivf) InvokeFunction produces a check for the parameter count,
     // even though we are certain to pass the correct number of arguments here.
     HInstruction* instr = New<HInvokeFunction>(function, 3);
     return ast_context()->ReturnInstruction(instr, expr->id());
   } else if (proxy != NULL) {
     Variable* var = proxy->var();
     if (var->IsUnallocated()) {
       Bailout(kDeleteWithGlobalVariable);
     } else if (var->IsStackAllocated() || var->IsContextSlot()) {
-      // Result of deleting non-global variables is false.  'this' is not really
-      // a variable, though we implement it as one.  The subexpression does not
-      // have side effects.
-      HValue* value = var->HasThisName(isolate()) ? graph()->GetConstantTrue()
-                                                  : graph()->GetConstantFalse();
+      // Result of deleting non-global variables is false.  'this' is not
+      // really a variable, though we implement it as one.  The
+      // subexpression does not have side effects.
+      HValue* value = var->is_this()
+          ? graph()->GetConstantTrue()
+          : graph()->GetConstantFalse();
       return ast_context()->ReturnValue(value);
     } else {
       Bailout(kDeleteWithNonGlobalVariable);
     }
   } else {
     // Result of deleting non-property, non-variable reference is true.
     // Evaluate the subexpression for side effects.
     CHECK_ALIVE(VisitForEffect(expr->expression()));
     return ast_context()->ReturnValue(graph()->GetConstantTrue());
   }
@@ skipping 2959 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8