Use a different map to distinguish eval contexts

src/contexts-inl.h

 // Copyright 2015 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.
 
 #ifndef V8_CONTEXTS_INL_H_
 #define V8_CONTEXTS_INL_H_
 
 #include "src/contexts.h"
 #include "src/objects-inl.h"
 
@@ skipping 100 matching lines @@
   Map* map = this->map();
   return map == map->GetHeap()->block_context_map();
 }
 
 
 bool Context::IsModuleContext() {
   Map* map = this->map();
   return map == map->GetHeap()->module_context_map();
 }
 
+bool Context::IsEvalContext() {
+  Map* map = this->map();
+  return map == map->GetHeap()->eval_context_map();
+}
 
 bool Context::IsScriptContext() {
   Map* map = this->map();
   return map == map->GetHeap()->script_context_map();
 }
 
 bool Context::OptimizedCodeMapIsCleared() {
   return osr_code_table() == GetHeap()->empty_fixed_array();
 }
 
@@ skipping 17 matching lines @@
     return type::cast(get(index));                        \
   }
 NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS)
 #undef NATIVE_CONTEXT_FIELD_ACCESSORS
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CONTEXTS_INL_H_