FreeBSD_HEAD_i386 - Build #4628 - Fixed

FreeBSD_HEAD_i386 - Build #4628 - Fixed:

Build information: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/4628/
Full change log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/4628/changes
Full build log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/4628/console

Change summaries:

311925 by ngie:
Import testcase updates with code contributed back to NetBSD

This also (inadvertently) contains an update to
contrib/netbsd-tests/lib/libc/sys/t_wait.c (new testcases).

MFC after:		2 weeks
In collaboration with:	christos_at_NetBSD.org

311924 by ngie:
Fix whitespace in comment

MFC after:	3 days

311923 by ngie:
Add acpi_if.h and opt_acpi.h to Makefile to unbreak "make depend" with
sys/modules/sdhci_acpi

MFC after:	6 days
X-MFC with:	r311911
Reported by:	Jenkins

311919 by ngie:
Partially revert r311236

There's no sense in trying to close a file descriptor from the negative cases
with unlink_test; it's best to ignore these cases.

The mkfifo case does make sense to keep though.

MFC after:	3 days

311918 by hrs:
Add more #ifdef INET and INET6.

311917 by ngie:
Fix up r311227

Check for creat returning a value != -1, not a non-zero value

MFC after:	3 days
Pointyhat to:	ngie
Reported by:	Coverity
CID:		1368366