Fix for: cc65 forgetting to emit labels (Alan Cox)

Alan Cox provided this on 2014-10-02 on the cc65.org mailing list:

http://www.cc65.org/mailarchive/2014-10/11673.html
[...]
It breaks in several spots with cc65 where cc65 forgets to emit the
labels for the goto statements - the code is there but with no label
and it them blows up linking
[...]

He also provided a fix:
http://www.cc65.org/mailarchive/2014-10/11675.html

which was approved by Uz:
http://www.cc65.org/mailarchive/2014-10/11679.html

This is the patch of Alan Cox, adjusted only to the new locations on
cc65/github.
Merge pull request #137 from spiro-trikaliotis/notemittinglabels-alancox

Fix for: cc65 forgetting to emit labels (Alan Cox)