Make .pre-process-tag-omission.pl handle linebreak

This change makes the .pre-process-tag-omission.pl script work as expected in
the case where a heading for an element section breaks across multiple lines.

Otherwise, without this change, the script fails for a case like this:

  <h4 element data-lt="meta" id="the-meta-element">The <dfn id="meta"><code>meta</code></dfn>
  element</h4>

...that is, a case where the "element</h4>" part isn’t on the same line as the
"<code>meta</code></dfn>" part.

Author: sideshowbarker

.pre-process-tag-omission.pl

@@ -27,7 +27,8 @@ sub pushLine {
             $mode = 'optionals';
         } elsif ($_ eq "   <dt><dfn>Void elements</dfn></dt>\n") {
             $mode = 'voids';
-        } elsif ($_ =~ m!<code>([^<]+)</code></dfn> elements?</h4>!) {
+        } elsif ($_ =~ m!<code>([^<]+)</code></dfn> elements?</h4>!
+          || $_ =~ m!id="the-[^-]+-element"[^>]*>The <dfn[^>]*><code>([^<]+)</code>!) {
             $current = $1;
             $mode = 'element';
         }
@@ -37,8 +38,6 @@ sub pushLine {
             push(@lines, \$line);
             $insertionPoints{$current} = \$line;
             $mode = 'bored';
-        } elsif ($_ =~ m!</h!) {
-            die 'confused';
         } else {
             # ignore...
         }