Cross building pcc

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

I tried adding MKPCC=yes to a mac68k build done on a NetBSD/amd64 system
and got the following error:

/u1/src/external/bsd/pcc/libexec/ccom/../../dist/pcc/mip/regs.c: In function 'ad
dalledges':
/u1/src/external/bsd/pcc/libexec/ccom/../../dist/pcc/mip/regs.c:793:3: error: ri
ght shift count >= width of type [-Werror]
   k = (live[i/NUMBITS] >> 32);
   ^

What I think is causing this is that the mkext tool in pcc is picking up
the size of NUMBITS from the host machine rather than generating the
correct value for the target.

Robert Swindells