Softfloat build fixes - Please review

[Nat Sloss <nathanialsloss%yahoo.com.au@localhost>]

Hi,

I've recently been trying to get m68k to work with softfloat.c (from libc).  
m68k has its own softfloat functions in libgcc_s.

These changesets allow m68k to use libc's softfloat (MKSOFTFLOAT=yes 
MKLIBCSOFTFLOAT=yes (which defaults to yes)).

It is also possible by setting MKLIBCSOFTFLOAT=no MKSOFTFLOAT=yes to build.sh 
to use the libgcc_s softfloat functions.

Other ports that use softfloat remain unchanged by these patches.

The patches can be found at:

http://ftp.netbsd.org/pub/NetBSD/misc/nat/libcsoftfloat/

There are 4 changes labelled newsoftfloat.1.diff to newsoftfloat.4.diff

The fisrt patch is the bulk of the changes required adding and utilizing the 
new build variables.

The second defines missing variables when building the libgcc_s m68k softfloat 
as most of the libc softfloat files are not built in this case.

The thrid patch is trivial as there is an issue building the libm tests on 
m68k at -O2.

The fourth patch - the one im **UNSURE ABOUT** contains a change to mknative 
which I dont know works as I don't know how to run mknative to verify the 
defs.mk output. 

I really need help with this one.

In the forth patch (newsoftfloat.4.diff):

defs.mk contains a sample of the required changes 
overrides.mk contains the changes to append to defs.mk by mknative.

The mknative patch is my attempt at doing this but I don't know if it is 
correct.


Am I OK to commit patches 1-3?   (as patch 4 will need more consideration).


Best regards and TIA,

Nat