Equality problem (Ullrich von Bassewitz)

Neil Stockbridge reported a problem with equality comparisons on
cc65.org's mailing list:

http://www.cc65.org/mailarchive/2014-10/11680.html

Uz provided a fix for it:

http://www.cc65.org/mailarchive/2014-10/11683.html

This pull request ask to add the fix to cc65 on github.