[api] add API for Promise status and result.

src/counters.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_COUNTERS_H_
 #define V8_COUNTERS_H_
 
 #include "include/v8.h"
 #include "src/allocation.h"
 #include "src/base/atomic-utils.h"
@@ skipping 610 matching lines @@
   V(Object_ToString)                                       \
   V(Object_ToUint32)                                       \
   V(Object_Uint32Value)                                    \
   V(Persistent_New)                                        \
   V(Private_New)                                           \
   V(Promise_Catch)                                         \
   V(Promise_Chain)                                         \
   V(Promise_HasRejectHandler)                              \
   V(Promise_Resolver_New)                                  \
   V(Promise_Resolver_Resolve)                              \
+  V(Promise_Result)                                        \
+  V(Promise_Status)                                        \
   V(Promise_Then)                                          \
   V(Proxy_New)                                             \
   V(RangeError_New)                                        \
   V(ReferenceError_New)                                    \
   V(RegExp_New)                                            \
   V(ScriptCompiler_Compile)                                \
   V(ScriptCompiler_CompileFunctionInContext)               \
   V(ScriptCompiler_CompileUnbound)                         \
   V(Script_Run)                                            \
   V(Set_Add)                                               \
@@ skipping 688 matching lines @@
 
   explicit Counters(Isolate* isolate);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COUNTERS_H_