re: GCC 5.x and ia64 and MKMAINTAINERTOOLS failing

[matthew green <mrg%eterna.com.au@localhost>]

> So I added
>    #define IA64_NO_LIBGCC_TFMODE
> to
>    src/external/gpl3/gcc/dist/gcc/config/ia64/netbsd.h
> and everything compiled.  That define is also in vms.h, elf.h, and
> freebsd.h. I am not sure if
> 	#define IA64_NO_LIBGCC_XFMODE
> is also needed or to be used instead of _TFMODE.  Maybe someone knows
> already, but I guess they have something to do with the size of
> floats?

let's assume we'll use the same choices here that freebsd does,
and when userland becomes more real, we can fix this if needed.

i've commited this change (and another).  let us know how the
testing goes now.

thanks.