Editorial: Add underscores to alias (#3566)

Author: jmdyck

spec.html

@@ -39595,7 +39595,7 @@ <h1>The %RegExpStringIteratorPrototype% Object</h1>
           <h1>%RegExpStringIteratorPrototype%.next ( )</h1>
           <emu-alg>
             1. Let _O_ be the *this* value.
-            1. If O is not an Object, throw a *TypeError* exception.
+            1. If _O_ is not an Object, throw a *TypeError* exception.
             1. If _O_ does not have all of the internal slots of a RegExp String Iterator Object Instance (see <emu-xref href="#sec-properties-of-regexp-string-iterator-instances"></emu-xref>), throw a *TypeError* exception.
             1. If _O_.[[Done]] is *true*, then
               1. Return CreateIteratorResultObject(*undefined*, *true*).