Fix complex condition in for/while/until

[aycabta]

The parse_statements method calls skip_optional_do_after_expression in case of for/while/until tokens. The skip_optional_do_after_expression uses get_end_token for checking end of loop condition expressions, but it's not correct, because the end is detected by only do token, newline and semi-colon token.

For example,

class Foo
  def blah()
    for i in (k+1)...n do
    end
    for i in (k+1)...n
    end
  end
end

This code is highlighted below:

<pre>
  <span class="ruby-keyword">def</span> <span class="ruby-identifier">blah</span>()
    <span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> (<span class="ruby-identifier">k</span><span class="ruby-operator">+</span><span class="ruby-value">1</span>)<span class="ruby-operator">...</span><span class="ruby-identifier">n</span> <span class="ruby-keyword">do</span>
    <span class="ruby-keyword">end</span>
    <span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> (<span class="ruby-identifier">k</span><span class="ruby-operator">+</span><span class="ruby-value">1</span>)<span class="ruby-operator">...</span><span class="ruby-identifier">n</span>
    <span class="ruby-keyword">end</span>
  <span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
</pre>

I think this is broken. This Pull Request fixes it:

<pre>
<span class="ruby-keyword">def</span> <span class="ruby-identifier">blah</span>()
  <span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> (<span class="ruby-identifier">k</span><span class="ruby-operator">+</span><span class="ruby-value">1</span>)<span class="ruby-operator">...</span><span class="ruby-identifier">n</span> <span class="ruby-keyword">do</span>
  <span class="ruby-keyword">end</span>
  <span class="ruby-keyword">for</span> <span class="ruby-identifier">i</span> <span class="ruby-keyword">in</span> (<span class="ruby-identifier">k</span><span class="ruby-operator">+</span><span class="ruby-value">1</span>)<span class="ruby-operator">...</span><span class="ruby-identifier">n</span>
  <span class="ruby-keyword">end</span>
<span class="ruby-keyword">end</span>
</pre>

[hsbt]

Confirmed. Thanks.