lang/gnatdroid-armv(5,7): Use lang/gcc-aux as base, not lang/gnat-aux
After a few additional patches for gcc-aux, gnatdroid-armv5 (and -armv7)
build and execute well when built and based on gcc 4.7-based gcc-aux.
The previous version was based on gcc 4.6-based gnat-aux. This was the
final port requiring gnat-aux, and now its part of the Ada framework.
Running acats using an ASUS Transformer XF101 (Android 4.0.3) as a target
results in a nearly perfect result. Only test cb1010a fails, which is
a failure to detect running out of stack space (-fstack-check). I intend
to investigate further, but as the only problem, gnatdroid remains a
highly capable compiler despite the small regression. Potentially
zero-cost exceptions were gained as a trade-off.