Normative: add Promise.withResolvers (tc39#3179)

spec.html

@@ -47029,6 +47029,20 @@ <h1>
         </emu-clause>
       </emu-clause>
 
+      <emu-clause id="sec-promise.withResolvers">
+        <h1>Promise.withResolvers ( )</h1>
+        <p>This function returns an object with three properties: a new promise together with the `resolve` and `reject` functions associated with it.</p>
+        <emu-alg>
+          1. Let _C_ be the *this* value.
+          1. Let _promiseCapability_ be ? NewPromiseCapability(_C_).
+          1. Let _obj_ be OrdinaryObjectCreate(%Object.prototype%).
+          1. Perform ! CreateDataPropertyOrThrow(_obj_, *"promise"*, _promiseCapability_.[[Promise]]).
+          1. Perform ! CreateDataPropertyOrThrow(_obj_, *"resolve"*, _promiseCapability_.[[Resolve]]).
+          1. Perform ! CreateDataPropertyOrThrow(_obj_, *"reject"*, _promiseCapability_.[[Reject]]).
+          1. Return _obj_.
+        </emu-alg>
+      </emu-clause>
+
       <emu-clause id="sec-get-promise-@@species">
         <h1>get Promise [ @@species ]</h1>
         <p>`Promise[@@species]` is an accessor property whose set accessor function is *undefined*. Its get accessor function performs the following steps when called:</p>