[runtime] Share constructor/non-constructor bound function maps.

src/bootstrapper.cc

 // Copyright 2014 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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/code-stubs.h"
@@ skipping 748 matching lines @@
   // Later the map is replaced with writable prototype map, allocated below.
   Handle<Map> strict_function_map =
       CreateStrictFunctionMap(FUNCTION_WITH_READONLY_PROTOTYPE, empty);
   native_context()->set_strict_function_map(*strict_function_map);
 
   // The final map for the strict mode functions. Writeable prototype.
   // This map is installed in MakeFunctionInstancePrototypeWritable.
   strict_function_map_writable_prototype_ =
       CreateStrictFunctionMap(FUNCTION_WITH_WRITEABLE_PROTOTYPE, empty);
 
-  // Special map for bound functions.
-  Handle<Map> bound_function_map =
+  // Special map for non-constructor bound functions.
+  // TODO(bmeurer): Bound functions should not be represented as JSFunctions.
+  Handle<Map> bound_function_without_constructor_map =
       CreateStrictFunctionMap(BOUND_FUNCTION, empty);
-  native_context()->set_bound_function_map(*bound_function_map);
+  native_context()->set_bound_function_without_constructor_map(
+      *bound_function_without_constructor_map);
+
+  // Special map for constructor bound functions.
+  // TODO(bmeurer): Bound functions should not be represented as JSFunctions.
+  Handle<Map> bound_function_with_constructor_map =
+      Map::Copy(bound_function_without_constructor_map, "IsConstructor");
+  bound_function_with_constructor_map->set_is_constructor(true);
+  native_context()->set_bound_function_with_constructor_map(
+      *bound_function_with_constructor_map);
 }
 
 
 void Genesis::CreateStrongModeFunctionMaps(Handle<JSFunction> empty) {
   // Allocate map for strong mode instances, which never have prototypes.
   Handle<Map> strong_function_map = CreateStrongFunctionMap(empty, false);
   native_context()->set_strong_function_map(*strong_function_map);
   // Constructors do, though.
   Handle<Map> strong_constructor_map = CreateStrongFunctionMap(empty, true);
   native_context()->set_strong_constructor_map(*strong_constructor_map);
@@ skipping 2486 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8