Fix perl completion with space between option and argument (bug #614775)

As reported in Debian bug #614775 [1], perl commands are being completed
with erroneous syntax for the '-d', '-V', and '-M' options, where a
space between the option and the option argument is not allowed.  This
is also true for the '-I' option.  This commit fixes this problem with a
Debian patch, which has been forwarded upstream.

Thanks to Jeff King for reporting and providing a patch.

[1] https://bugs.debian.org/614775