Revert previous again.

There are claims that it still violates strict-aliasing rule and
it is no sense to just appease compiler by incorrect implementation.
Specify -fno-strict-aliasing as a temporary workaround for gcc48.

The existing abcksum() also violates strict-aliasing rule
(while current gcc48 doesn't warn it) and fixing all violations
strictly requires whole reorganization of boot sector structures.
But it won't happen soon and this MD installboot should be integrated
into MI installboot(8) in future, and it requires whole overhaul anyway.
See long discussion in source-changes-d@ for details.

Should be pulled up to netbsd-7 if we switches m68k to using gcc48.
Add PCIe CRS Software Visibility bit.
Disable "OS bootversion check" on crunched binaries for installation media.

This oscheck() function seems implemented to check compatibility
between bootloaders and /netbsd kernel, but checking /netbsd using kvm(3)
doesn't make sense on installation or even future cross builds, and
probably we will never bump bootloader version without compatibility
per recent 14 years history.

This works around overflow of 1440KB 2HD sysinst.fs, and would also be
worth to pullup to netbsd-7.
Shrink GENERIC and enable options MODULAR instead, as other poor m68k ports.

This allows all (at least ATARITT and FALCON, which have certain users)
gzipped kernel binaries put into 1440KB 2HD floppy so that users can
load these kernels on the native TOS using LOADBSD.TTP utility for
installation.  Note SMALL030 kernel doesn't include any Ethernet
configuration and requires CD-ROM or other removable disks.

Should be pulled up to netbsd-7.
Regen config files from GENERIC.in rev 1.109 by makeconf:

> Shrink GENERIC and enable options MODULAR instead, as other poor m68k ports.
>
> This allows all (at least ATARITT and FALCON, which have certain users)
> gzipped kernel binaries put into 1440KB 2HD floppy so that users can
> load these kernels on the native TOS using LOADBSD.TTP utility for
> installation.  Note SMALL030 kernel doesn't include any Ethernet
> configuration and requires CD-ROM or other removable disks.
>
> Should be pulled up to netbsd-7.