[PATCH] Don't check HAVE_UNISTD_H

[Tom Tromey]

>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:

Simon> LGTM.  Maybe we could even remove all includes of unistd.h except the
Simon> one in defs.h, since defs.h is known to be included first in every
Simon> source file.  But they are harmless so it's probably not worth the
Simon> effort.

Alternatively we could get rid of the one in defs.h and try to have
headers include what they use.  I'm not sure which is better really.
Anyway, I agree that it all seems relatively harmless, so I didn't make
any changes here.

Tom