Lookahead for :// no longer needed

Author: ondrejmirtes

src/Lexer/Lexer.php

@@ -163,7 +163,7 @@ private function generateRegexp(): string
 			self::TOKEN_CLOSE_CURLY_BRACKET => '\\}',
 
 			self::TOKEN_COMMA => ',',
-			self::TOKEN_COMMENT => '(?<![:/])\/\/[^\\r\\n]*(?=\n|\r|\*/)',
+			self::TOKEN_COMMENT => '\/\/[^\\r\\n]*(?=\n|\r|\*/)',
 			self::TOKEN_VARIADIC => '\\.\\.\\.',
 			self::TOKEN_DOUBLE_COLON => '::',
 			self::TOKEN_DOUBLE_ARROW => '=>',