Editorial: Don't say that a built-in function can be an ECMAScript fu…

…nction (tc39#3145)

spec.html

@@ -13723,14 +13723,13 @@ <h1>
 
   <emu-clause id="sec-built-in-function-objects">
     <h1>Built-in Function Objects</h1>
-    <p>The built-in function objects defined in this specification may be implemented as either ECMAScript function objects (<emu-xref href="#sec-ecmascript-function-objects"></emu-xref>) whose behaviour is provided using ECMAScript code or as function objects whose behaviour is provided in some other manner. In either case, the effect of calling such functions must conform to their specifications. An implementation may also provide additional built-in function objects that are not defined in this specification.</p>
-    <p>If a built-in function object is implemented as an ECMAScript function object, it must have all the internal slots described in <emu-xref href="#sec-ecmascript-function-objects"></emu-xref> ([[Prototype]], [[Extensible]], and the slots listed in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects"></emu-xref>), and [[InitialName]]. The value of the [[InitialName]] internal slot is a String value that is the initial name of the function. It is used by <emu-xref href="#sec-function.prototype.tostring"></emu-xref>.</p>
-    <p>Built-in function objects must have the ordinary object behaviour specified in <emu-xref href="#sec-ordinary-object-internal-methods-and-internal-slots"></emu-xref>. All such function objects have [[Prototype]], [[Extensible]], [[Realm]], and [[InitialName]] internal slots, with the same meanings as above.</p>
+    <p>For a built-in function object defined in this specification, the effect of calling such a function must conform to its specification. An implementation may also provide additional built-in function objects that are not defined in this specification.</p>
+    <p>Built-in function objects must have the ordinary object behaviour specified in <emu-xref href="#sec-ordinary-object-internal-methods-and-internal-slots"></emu-xref>. All such function objects have [[Prototype]], [[Extensible]], [[Realm]], and [[InitialName]] internal slots. [[Realm]] has the same meaning as in <emu-xref href="#table-internal-slots-of-ecmascript-function-objects"></emu-xref>. The value of the [[InitialName]] internal slot is a String value that is the initial name of the function. It is used by <emu-xref href="#sec-function.prototype.tostring"></emu-xref>.</p>
     <p>Unless otherwise specified every built-in function object has the %Function.prototype% object as the initial value of its [[Prototype]] internal slot.</p>
-    <p>The behaviour specified for each built-in function via algorithm steps or other means is the specification of the function body behaviour for both [[Call]] and [[Construct]] invocations of the function. However, [[Construct]] invocation is not supported by all built-in functions. For each built-in function, when invoked with [[Call]], the [[Call]] _thisArgument_ provides the *this* value, the [[Call]] _argumentsList_ provides the named parameters, and the NewTarget value is *undefined*. When invoked with [[Construct]], the *this* value is uninitialized, the [[Construct]] _argumentsList_ provides the named parameters, and the [[Construct]] _newTarget_ parameter provides the NewTarget value. If the built-in function is implemented as an ECMAScript function object then this specified behaviour must be implemented by the ECMAScript code that is the body of the function. Built-in functions that are ECMAScript function objects must be strict functions. If a built-in constructor has any [[Call]] behaviour other than throwing a *TypeError* exception, an ECMAScript implementation of the function must be done in a manner that does not cause the function's [[IsClassConstructor]] internal slot to have the value *true*.</p>
+    <p>The behaviour specified for each built-in function via algorithm steps or other means is the specification of the function body behaviour for both [[Call]] and [[Construct]] invocations of the function. However, [[Construct]] invocation is not supported by all built-in functions. For each built-in function, when invoked with [[Call]], the [[Call]] _thisArgument_ provides the *this* value, the [[Call]] _argumentsList_ provides the named parameters, and the NewTarget value is *undefined*. When invoked with [[Construct]], the *this* value is uninitialized, the [[Construct]] _argumentsList_ provides the named parameters, and the [[Construct]] _newTarget_ parameter provides the NewTarget value.</p>
     <p>Built-in function objects that are not identified as constructors do not implement the [[Construct]] internal method unless otherwise specified in the description of a particular function. When a built-in constructor is called as part of a `new` expression the _argumentsList_ parameter of the invoked [[Construct]] internal method provides the values for the built-in constructor's named parameters.</p>
     <p>Built-in functions that are not constructors do not have a *"prototype"* property unless otherwise specified in the description of a particular function.</p>
-    <p>If a built-in function object is not implemented as an ECMAScript function it must provide [[Call]] and [[Construct]] internal methods that conform to the following definitions:</p>
+    <p>A built-in function object must provide [[Call]] and [[Construct]] internal methods that conform to the following definitions:</p>
 
     <emu-clause id="sec-built-in-function-objects-call-thisargument-argumentslist" type="internal method">
       <h1>