Add the HostSystemUTCEpochNanoseconds abstract operation

Context: tc39/proposal-temporal#1654.

source

@@ -2937,6 +2937,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-automatic-semicolon-insertion">automatic semicolon insertion</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-candidate-executions">candidate execution</dfn></li>
      <li>The <dfn data-x-href="https://tc39.es/ecma262/#current-realm">current realm</dfn></li>
+     <li><dfn data-x-href="https://tc39.es/ecma262/#clamping">clamping</dfn> a mathematical value</li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#early-error-rule">early error</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-forward-progress">forward progress</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-invariants-of-the-essential-internal-methods">invariants of the essential internal methods</dfn></li>
@@ -3110,6 +3111,15 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
     <ul class="brief">
      <li>The <dfn data-x-href="https://tc39.es/proposal-resizablearraybuffer/#sec-isarraybufferviewoutofbounds">IsArrayBufferViewOutOfBounds</dfn> abstract operation</li>
     </ul>
+
+    <p>User agents that support JavaScript must also implement the <cite>Temporal</cite> proposal.
+    The following terms are defined there, and used in this specification: <ref>JSTEMPORAL</ref></p>
+
+    <ul class="brief">
+     <li>The <dfn data-x="js-HostSystemUTCEpochNanoseconds" data-x-href="https://tc39.es/proposal-temporal/#sec-hostsystemutcepochnanoseconds">HostSystemUTCEpochNanoseconds</dfn> abstract operation</li>
+     <li>The <dfn data-x-href="https://tc39.es/proposal-temporal/#eqn-nsMaxInstant">nsMaxInstant</dfn> and
+         <dfn data-x-href="https://tc39.es/proposal-temporal/#eqn-nsMinInstant">nsMinInstant</dfn> values</li>
+    </ul>
    </dd>
 
    <dt>WebAssembly</dt>
@@ -3406,20 +3416,20 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://fullscreen.spec.whatwg.org/#fullscreen-flag">fullscreen flag</dfn></li>
     </ul>
 
-    <p><cite>High Resolution Time</cite> provides the <dfn
-    data-x-href="https://w3c.github.io/hr-time/#dfn-current-high-resolution-time">current high
-    resolution time</dfn>, the <dfn
-    data-x-href="https://w3c.github.io/hr-time/#dfn-relative-high-resolution-time">relative high
-    resolution time</dfn>, the <dfn
-    data-x-href="https://w3c.github.io/hr-time/#dfn-unsafe-shared-current-time">unsafe shared
-    current time</dfn>, the <dfn
-    data-x-href="https://w3c.github.io/hr-time/#dfn-shared-monotonic-clock">shared monotonic clock</dfn>,
-    the <dfn data-x-href="https://w3c.github.io/hr-time/#dfn-unsafe-moment">unsafe moment</dfn>,
-    the <dfn data-x-href="https://w3c.github.io/hr-time/#dfn-duration-from">duration from</dfn>,
-    the <dfn data-x-href="https://w3c.github.io/hr-time/#dfn-coarsen-time">coarsen time</dfn>
-    algorithm, and the <dfn
-    data-x-href="https://w3c.github.io/hr-time/#dom-domhighrestimestamp"><code>DOMHighResTimeStamp</code></dfn>
-    typedef. <ref>HRT</ref></p>
+    <p><cite>High Resolution Time</cite> provides the following features: <ref>HRT</ref></p>
+
+    <ul class="brief">
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-current-high-resolution-time">current high resolution time</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-relative-high-resolution-time">relative high resolution time</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-unsafe-shared-current-time">unsafe shared current time</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-shared-monotonic-clock">shared monotonic clock</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-unsafe-moment">unsafe moment</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-duration-from">duration from</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-coarsen-time">coarsen time</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-current-wall-time">current wall time</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dfn-unix-epoch">Unix epoch</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/hr-time/#dom-domhighrestimestamp"><code>DOMHighResTimeStamp</code></dfn></li>
+    </ul>
    </dd>
 
 
@@ -109010,6 +109020,26 @@ dictionary <dfn dictionary>PromiseRejectionEventInit</dfn> : <span>EventInit</sp
    </li>
   </ol>
 
+  <h5 id="hostsystemutcepochnanoseconds"><dfn>HostSystemUTCEpochNanoseconds</dfn>(<var>global</var>)</h5>
+
+  <p>The Temporal proposal contains an <span>implementation-defined</span> <span
+  data-x="js-HostSystemUTCEpochNanoseconds">HostSystemUTCEpochNanoseconds</span> abstract operation.
+  User agents must use the following implementation: <ref>JSTEMPORAL</ref></p>
+
+  <ol>
+   <li><p>Let <var>settingsObject</var> be <var>global</var>'s <span>relevant settings
+   object</span>.</p></li>
+
+   <li><p>Let <var>time</var> be <var>settingsObject</var>'s <span>current wall
+   time</span>.</p></li>
+
+   <li><p>Let <var>ns</var> be the number of nanoseconds from the <span>Unix epoch</span> to
+   <var>time</var>, rounded to the nearest integer.</p></li>
+
+   <li><p>Return the result of <span>clamping</span> <var>ns</var> between
+   <span>nsMinInstant</span> and <span>nsMaxInstant</span>.</p></li>
+  </ol>
+
   <h5 id="integration-with-javascript-jobs">Job-related host hooks</h5>
 
   <p>The JavaScript specification defines Jobs to be scheduled and run later by the host, as well as
@@ -143232,6 +143262,9 @@ INSERT INTERFACES HERE
    <dt id="refsJSON">[JSON]</dt>
    <dd><cite><a href="https://www.rfc-editor.org/rfc/rfc8259">The JavaScript Object Notation (JSON) Data Interchange Format</a></cite>, T. Bray. IETF.</dd>
 
+   <dt id="refsJSTEMPORAL">[JSTEMPORAL]</dt>
+   <dd><cite><a href="https://tc39.es/proposal-temporal/">Temporal</a></cite>. Ecma International.</dd>
+
    <dt id="refsLONGTASKS">[LONGTASKS]</dt>
    <dd><cite><a href="https://w3c.github.io/longtasks/">Long Tasks</a></cite>, D. Denicola, I. Grigorik, S. Panicker. W3C.</dd>