MIPS libstdc++-v3 x86-x-mips-elf doesn't build

[Graham Stott]

Hi

I'm trying to build a x86-x-mips-elf toolchain for testing MIPS patches
using gcc + binutils + newlib + gdb. 

Since this patch by HJL I have been unable to build libsdtc++ for a
x86-x-mips-elf toolchain.

2001-07-25  H.J. Lu <hjl@gnu.org>

        * configure.target (cpu_include_dir): Set to `config/cpu/mips'
        for mips.

        * config/cpu/mips/bits/atomicity.h: New.

The problem is atomicity.h includes <sgidefs.h> which looks like its
a header file with some SGI definitions. 

What gives? I'm not targeting a SGI target so I don't expect to need
any SGI header files.

The other thing is I'm not targeting IRIS5, IRIS6 or Linux so both
_MIPS_ISA and _MIPS_ISA_MIPS1 are undefined. This leads to a problem
because then the preprocessor test (_MIPS_ISA >= _MIPS_ISA_MIPS1) then
evaluates to true and we think we are targeting a MIPS2 or greater ISA.

For the moment I've hacked up my atomicity.h so that I can build libstdc++v3

Graham