[Bug ada/85007] -b flag to gnatlink not recognized

[emr-gnu at hev dot psu.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85007

--- Comment #12 from Eric Reischer <emr-gnu at hev dot psu.edu> ---
It's in there on my target system; I just missed it when I was transcribing
over into the report.

It looks from gnatlink.adb:540 (of 7.3.0), if the "--GCC=" flag is specified,
it short-circuits all other args that normally would have been passed to the
linker, including the optimization level, "-m32", "--RTS=32", and any other
flags that were passed in the compiler section of the GPR file.