Bug#781457: ada bootstrap failure on mips and mipsel

Package: src:gcc-5
Version: 5-20150327-1
Severity: important
Tags: sid stretch
Forwarded: https://gcc.gnu.org/PR65618

seen building trunk 20150328. I'm not entirely sure if this is a regression.
Apparently all distro builds for mips and mipsel set STAGE3_CFLAGS += -gtoggle
(same as in stage2) in the past, and maybe were papering over the problem.

If this workaround is really needed, we should limit the comparision failure to
exactly the one failing file.

Comparing stages 2 and 3
warning: gcc/cc1-checksum.o differs
warning: gcc/cc1objplus-checksum.o differs
warning: gcc/cc1obj-checksum.o differs
warning: gcc/cc1plus-checksum.o differs
Bootstrap comparison failure!
gcc/ada/a-except.o differs
Makefile:22697: recipe for target 'compare' failed
make[4]: *** [compare] Error 1