Drop is_eval_scope when checking how to access dynamic globals. It has no influence

src/full-codegen/x64/full-codegen-x64.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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1132 matching lines @@
         // Check that extension is "the hole".
         __ JumpIfNotRoot(ContextOperand(context, Context::EXTENSION_INDEX),
                          Heap::kTheHoleValueRootIndex, slow);
       }
       // Load next context in chain.
       __ movp(temp, ContextOperand(context, Context::PREVIOUS_INDEX));
       // Walk the rest of the chain without clobbering rsi.
       context = temp;
     }
     // If no outer scope calls eval, we do not need to check more
-    // context extensions.  If we have reached an eval scope, we check
-    // all extensions from this point.
-    if (!s->outer_scope_calls_sloppy_eval() || s->is_eval_scope()) break;
+    // context extensions.
+    if (!s->outer_scope_calls_sloppy_eval()) break;
     s = s->outer_scope();
   }
 
-  if (s != NULL && s->is_eval_scope()) {
-    // Loop up the context chain.  There is no frame effect so it is
-    // safe to use raw labels here.
-    Label next, fast;
-    if (!context.is(temp)) {
-      __ movp(temp, context);
-    }
-    // Load map for comparison into register, outside loop.
-    __ LoadRoot(kScratchRegister, Heap::kNativeContextMapRootIndex);
-    __ bind(&next);
-    // Terminate at native context.
-    __ cmpp(kScratchRegister, FieldOperand(temp, HeapObject::kMapOffset));
-    __ j(equal, &fast, Label::kNear);
-    // Check that extension is "the hole".
-    __ JumpIfNotRoot(ContextOperand(temp, Context::EXTENSION_INDEX),
-                     Heap::kTheHoleValueRootIndex, slow);
-    // Load next context in chain.
-    __ movp(temp, ContextOperand(temp, Context::PREVIOUS_INDEX));
-    __ jmp(&next);
-    __ bind(&fast);
-  }
-
   // All extension objects were empty and it is safe to use a normal global
   // load machinery.
   EmitGlobalVariableLoad(proxy, typeof_mode);
 }
 
 
 MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(Variable* var,
                                                                 Label* slow) {
   DCHECK(var->IsContextSlot());
   Register context = rsi;
@@ skipping 2472 matching lines @@
   DCHECK_EQ(
       isolate->builtins()->OnStackReplacement()->entry(),
       Assembler::target_address_at(call_target_address, unoptimized_code));
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64