port-i386/49665: 7.0 install not bootable if installing over GPT disk

[jmcneill%invisible.ca@localhost]

>Number:         49665
>Category:       port-i386
>Synopsis:       7.0 install not bootable if installing over GPT disk
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Feb 14 12:30:00 +0000 2015
>Originator:     Jared McNeill
>Release:        7.0_BETA
>Organization:
>Environment:
>Description:
If you install 7.0_BETA or -current i386/amd64 (selecting "use entire disk" in the installer) on a disk that already had a GPT, the resulting system is left unbootable.
>How-To-Repeat:
Install FreeBSD 10.1-RELEASE, then try to install NetBSD 7.0_BETA or -current over top of it.
>Fix: