Editorial: Remove "message" property from list of Error differences (#…

…3292)

This language is a holdover from ES3, the "message" property of all Error prototype objects is defined to be the empty string since ES5.

Co-authored-by: Andrew Drake <adrake@adrake.org>
Co-authored-by: Kevin Gibbons <bakkot@gmail.com>

spec.html

@@ -30859,7 +30859,7 @@ <h1>
   <emu-clause id="sec-error-objects">
     <h1>Error Objects</h1>
     <p>Instances of Error objects are thrown as exceptions when runtime errors occur. The Error objects may also serve as base objects for user-defined exception classes.</p>
-    <p>When an ECMAScript implementation detects a runtime error, it throws a new instance of one of the _NativeError_ objects defined in <emu-xref href="#sec-native-error-types-used-in-this-standard"></emu-xref> or a new instance of AggregateError object defined in <emu-xref href="#sec-aggregate-error-objects"></emu-xref>. Each of these objects has the structure described below, differing only in the name used as the constructor name instead of _NativeError_, in the *"name"* property of the prototype object, in the implementation-defined *"message"* property of the prototype object, and in the presence of the %AggregateError%-specific *"errors"* property.</p>
+    <p>When an ECMAScript implementation detects a runtime error, it throws a new instance of one of the _NativeError_ objects defined in <emu-xref href="#sec-native-error-types-used-in-this-standard"></emu-xref> or a new instance of the AggregateError object defined in <emu-xref href="#sec-aggregate-error-objects"></emu-xref>.</p>
 
     <emu-clause id="sec-error-constructor">
       <h1>The Error Constructor</h1>
@@ -30991,7 +30991,7 @@ <h1>URIError</h1>
 
     <emu-clause id="sec-nativeerror-object-structure">
       <h1>_NativeError_ Object Structure</h1>
-      <p>When an ECMAScript implementation detects a runtime error, it throws a new instance of one of the _NativeError_ objects defined in <emu-xref href="#sec-native-error-types-used-in-this-standard"></emu-xref>. Each of these objects has the structure described below, differing only in the name used as the constructor name instead of _NativeError_, in the *"name"* property of the prototype object, and in the implementation-defined *"message"* property of the prototype object.</p>
+      <p>Each of these objects has the structure described below, differing only in the name used as the constructor name and in the *"name"* property of the prototype object.</p>
       <p>For each error object, references to _NativeError_ in the definition should be replaced with the appropriate error object name from <emu-xref href="#sec-native-error-types-used-in-this-standard"></emu-xref>.</p>
 
       <emu-clause id="sec-nativeerror-constructors">