3.4/3.5 PATCH: Allow IRIX 5 Ada bootstrap

[Richard Kenner]

    ../../xgcc -B../../ -c -g -O2      -W -Wall -gnatpg  a-stwima.adb -o a-stwima.o
    a-stwima.adb:0: note: -g is only supported using GNU as,
    a-stwima.adb:0: note: -g option disabled
    +===========================GNAT BUG DETECTED==========================+
    | 3.5.0 20040119 (experimental) (mips-sgi-irix5.3) GCC error:          |
    | in handle_epilogue_set, at function.c:7584                           |
    | Error detected at a-stwima.adb:580:4                                 |

Just FYI, I have the fix for that, but I'm not putting it in because it won't
help much: you'll hit a similar abort a few functions down.  That one is
harder to fix, though I do plan to do so.