Reword internal methods vtable-as-brand prose

spec.html

@@ -2253,6 +2253,7 @@ <h1>Object Internal Methods and Internal Slots</h1>
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         </ul>
         <p>An <dfn id="exotic-object">exotic object</dfn> is an object that is not an ordinary object.</p>
+        <p>This specification recognizes different kinds of exotic objects by those objects' internal methods. An object that is behaviourally equivalent to a particular kind of exotic object (such as Array or Bound Function), but does not have the same collection of internal methods specified for that kind, is not recognized as that kind of exotic object.</p>
         <p>The &ldquo;Signature&rdquo; column of <emu-xref href="#table-5"></emu-xref> and other similar tables describes the invocation pattern for each internal method. The invocation pattern always includes a parenthesized list of descriptive parameter names. If a parameter name is the same as an ECMAScript type name then the name describes the required type of the parameter value. If an internal method explicitly returns a value, its parameter list is followed by the symbol &ldquo;&rarr;&rdquo; and the type name of the returned value. The type names used in signatures refer to the types defined in clause <emu-xref href="#sec-ecmascript-data-types-and-values"></emu-xref> augmented by the following additional names. &ldquo;<em>any</em>&rdquo; means the value may be any ECMAScript language type.</p>
         <p>In addition to its parameters, an internal method always has access to the object that is the target of the method invocation.</p>
         <p>An internal method implicitly returns a Completion Record, either a normal completion that wraps a value of the return type shown in its invocation pattern, or a throw completion.</p>