[promise] use PromiseCapabilities directly for Promise.race resolve/reject

Does not remove the extra private state added, as doing so seems to break the
debugger.

Fixes new Test262 tests:
- built-ins/Promise/race/same-resolve-function
- built-ins/Promise/race/same-reject-function

BUG=v8:4632
LOG=N
R=littledan@chromium.org, cbruni@chromium.org

Review URL: https://codereview.chromium.org/1538853002

Cr-Commit-Position: refs/heads/master@{#33214}

src/js/promise.js

@@ -394,9 +394,8 @@ function PromiseRace(iterable) {
   var deferred = NewPromiseCapability(this);
   try {
     for (var value of iterable) {
-      var reject = reason => { deferred.reject(reason); };
-      this.resolve(value).then((x) => { deferred.resolve(x) }, reject);
-      SET_PRIVATE(reject, promiseCombinedDeferredSymbol, deferred);
+      this.resolve(value).then(deferred.resolve, deferred.reject);
+      SET_PRIVATE(deferred.reject, promiseCombinedDeferredSymbol, deferred);
     }
   } catch (e) {
     deferred.reject(e)

test/test262/test262.status

@@ -403,10 +403,6 @@
   'language/expressions/generators/invoke-as-constructor': [FAIL],
   'language/expressions/object/method-definition/generator-invoke-ctor': [FAIL],
 
-  # https://bugs.chromium.org/p/v8/issues/detail?id=4632
-  'built-ins/Promise/race/same-resolve-function': [FAIL],
-  'built-ins/Promise/race/same-reject-function': [FAIL],
-
   # https://bugs.chromium.org/p/v8/issues/detail?id=4633
   'built-ins/Promise/reject-function-name': [FAIL],
   'built-ins/Promise/resolve-function-name': [FAIL],