Editorial: Change 0 to *+0*_F in 3 spots

The initial value of a 'length' property should be a Number,
so use the appropriate notation, after PR tc39#2007.

spec.html

@@ -26211,7 +26211,7 @@ <h1>Properties of the Function Prototype Object</h1>
         <li>does not have a [[Construct]] internal method; it cannot be used as a constructor with the `new` operator.</li>
         <li>has a [[Prototype]] internal slot whose value is %Object.prototype%.</li>
         <li>does not have a *"prototype"* property.</li>
-        <li>has a *"length"* property whose value is 0.</li>
+        <li>has a *"length"* property whose value is *+0*<sub>𝔽</sub>.</li>
         <li>has a *"name"* property whose value is the empty String.</li>
       </ul>
       <emu-note>
@@ -29550,7 +29550,7 @@ <h1>Properties of the String Prototype Object</h1>
         <li>is <dfn>%String.prototype%</dfn>.</li>
         <li>is a String exotic object and has the internal methods specified for such objects.</li>
         <li>has a [[StringData]] internal slot whose value is the empty String.</li>
-        <li>has a *"length"* property whose initial value is 0 and whose attributes are { [[Writable]]: *false*, [[Enumerable]]: *false*, [[Configurable]]: *false* }.</li>
+        <li>has a *"length"* property whose initial value is *+0*<sub>𝔽</sub> and whose attributes are { [[Writable]]: *false*, [[Enumerable]]: *false*, [[Configurable]]: *false* }.</li>
         <li>has a [[Prototype]] internal slot whose value is %Object.prototype%.</li>
       </ul>
       <p>Unless explicitly stated otherwise, the methods of the String prototype object defined below are not generic and the *this* value passed to them must be either a String value or an object that has a [[StringData]] internal slot that has been initialized to a String value.</p>
@@ -32884,7 +32884,7 @@ <h1>Properties of the Array Prototype Object</h1>
       <ul>
         <li>is <dfn>%Array.prototype%</dfn>.</li>
         <li>is an Array exotic object and has the internal methods specified for such objects.</li>
-        <li>has a *"length"* property whose initial value is 0 and whose attributes are { [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *false* }.</li>
+        <li>has a *"length"* property whose initial value is *+0*<sub>𝔽</sub> and whose attributes are { [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *false* }.</li>
         <li>has a [[Prototype]] internal slot whose value is %Object.prototype%.</li>
       </ul>
       <emu-note>