Editorial: "U" -> "UnicodeMode"

Fixes bug from PR tc39#2436.

(The renaming happened in PR tc39#2411.)

spec.html

@@ -36297,7 +36297,7 @@ <h1>
           1. If _u_ is *true*, then
             1. Let _parseResult_ be ParseText(_patternText_, |Pattern[+UnicodeMode, +N]|).
           1. Else,
-            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[~U, +N]|).
+            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[~UnicodeMode, +N]|).
           1. Return _parseResult_.
         </emu-alg>
       </emu-clause>
@@ -47643,11 +47643,11 @@ <h1>Static Semantics: ParsePattern ( _patternText_, _u_ )</h1>
         <p>The abstract operation ParsePattern takes arguments _patternText_ (a sequence of Unicode code points) and _u_ (a Boolean). It performs the following steps when called:</p>
         <emu-alg>
           1. If _u_ is *true*, then
-            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[+U, +N]|).
+            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[+UnicodeMode, +N]|).
           1. Else,
-            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[~U, ~N]|).
+            1. Let _parseResult_ be ParseText(_patternText_, |Pattern[~UnicodeMode, ~N]|).
             1. If _parseResult_ is a Parse Node and _parseResult_ contains a |GroupName|, then
-              1. Set _parseResult_ to ParseText(_patternText_, |Pattern[~U, +N]|).
+              1. Set _parseResult_ to ParseText(_patternText_, |Pattern[~UnicodeMode, +N]|).
           1. Return _parseResult_.
         </emu-alg>
       </emu-annex>