fix handling of shebang and preamble (#1545)

fixes #1332

lib/parse.js

@@ -558,6 +558,11 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
     function next_token(force_regexp) {
         if (force_regexp != null)
             return read_regexp(force_regexp);
+        if (shebang && S.pos == 0 && looking_at("#!")) {
+            start_token();
+            forward(2);
+            skip_line_comment("comment5");
+        }
         for (;;) {
             skip_whitespace();
             start_token();
@@ -589,13 +594,6 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
             if (PUNC_CHARS(ch)) return token("punc", next());
             if (OPERATOR_CHARS(ch)) return read_operator();
             if (code == 92 || is_identifier_start(code)) return read_word();
-            if (shebang) {
-                if (S.pos == 0 && looking_at("#!")) {
-                    forward(2);
-                    skip_line_comment("comment5");
-                    continue;
-                }
-            }
             break;
         }
         parse_error("Unexpected character '" + ch + "'");