Add full-width closing bracket support after asciiend

Allow ］ (U+FF3D) after asciiend in ASCII content scanner.
This enables ASCII strings inside arrays with full-width brackets:
  var x = ［ascii...asciiend］

The parser now correctly recognizes this as an array containing
an ASCII string, not as a syntax error.

Fixes 1 additional parsing error.

grammar.js

@@ -175,6 +175,7 @@ module.exports = grammar({
             $.string,
             $.boolean,
             $.null,
+            $.ascii_string,
             $.array,
             $.member_expression,
             $.call_expression,
@@ -186,7 +187,6 @@ module.exports = grammar({
             $.parenthesized_expression,
             $.new_statement,
             $.import_expression,
-            $.ascii_string,
             $.color_code
         ),
 
@@ -282,10 +282,7 @@ module.exports = grammar({
 
         null: $ => 'null',
 
-        ascii_string: $ => choice(
-            seq('ascii', $.ascii_content, 'asciiend'),
-            seq(choice('[', '［'), 'ascii', $.ascii_content, 'asciiend', choice(']', '］'))
-        )
+        ascii_string: $ => seq('ascii', $.ascii_content, 'asciiend')
     },
 
     extras: $ => [