Editorial: Simplify NewGlobalEnvironment

In NewDeclarativeEnvironment, allow parameter `_E_` to be `*null*`,
and in NewGlobalEnvironment, change
`a new declarative Environment Record containing no bindings`
to
`NewDeclarativeEnvironment(*null*)`

spec.html

@@ -11439,7 +11439,7 @@ <h1>
       <emu-clause id="sec-newdeclarativeenvironment" type="abstract operation">
         <h1>
           NewDeclarativeEnvironment (
-            _E_: an Environment Record,
+            _E_: an Environment Record or *null*,
           ): a Declarative Environment Record
         </h1>
         <dl class="header">
@@ -11501,7 +11501,7 @@ <h1>
         </dl>
         <emu-alg>
           1. Let _objRec_ be NewObjectEnvironment(_G_, *false*, *null*).
-          1. Let _dclRec_ be a new Declarative Environment Record containing no bindings.
+          1. Let _dclRec_ be NewDeclarativeEnvironment(*null*).
           1. Let _env_ be a new Global Environment Record.
           1. Set _env_.[[ObjectRecord]] to _objRec_.
           1. Set _env_.[[GlobalThisValue]] to _thisValue_.