bin/50610: Some gpt tests fail on sparc

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         50610
>Category:       bin
>Synopsis:       gpt tests fail on sparc
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 02 18:15:00 +0000 2016
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date >= 2015.12.08.01.57.13
>Organization:

>Environment:
System: NetBSD
Architecture: sparc
Machine: sparc
>Description:

The following test cases of the sbin/gpt/t_gpt test are failing on
sparc, and apparently have been ever since they were added in early
December:

  bootable_2part
  migrate_disklabel
  recover_backup

They are also failing on sparc64, based on martin's test logs.

>How-To-Repeat:

Run the ATF tests on sparc, or inspect the babylon5 test logs:

  http://releng.netbsd.org/b5reports/sparc/build/2015.12.08.01.57.13/test.html#sbin_gpt_t_gpt_bootable_2part

or martin's sparc64 test logs:

  http://www.netbsd.org/~martin/sparc64-atf/426_atf.html#failed-tcs-summary

>Fix: