Reland v8::Private and related APIs

src/heap/heap.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 259 matching lines @@
   V(minus_zero_string, "-0")                               \
   V(multiline_string, "multiline")                         \
   V(name_string, "name")                                   \
   V(nan_string, "NaN")                                     \
   V(next_string, "next")                                   \
   V(null_string, "null")                                   \
   V(number_string, "number")                               \
   V(Number_string, "Number")                               \
   V(object_string, "object")                               \
   V(Object_string, "Object")                               \
+  V(private_api_string, "private_api")                     \
   V(proto_string, "__proto__")                             \
   V(prototype_string, "prototype")                         \
   V(query_colon_string, "(?:)")                            \
   V(RegExp_string, "RegExp")                               \
   V(set_string, "set")                                     \
   V(Set_string, "Set")                                     \
   V(source_mapping_url_string, "source_mapping_url")       \
   V(source_string, "source")                               \
   V(source_url_string, "source_url")                       \
   V(stack_string, "stack")                                 \
@@ skipping 2431 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_