Bug#756096: libobjc4: Linking fails with undefined reference to `rs6000_special_adjust_field_align_p'

[Yavor Doganov <yavor@gnu.org>]

Package: libobjc4
Version: 4.9.1-2
Severity: important

The patches gcc-elfv2-abi-warn*.diff are apparently incomplete as
linking with libobjc fails on powerpc/ppc64/ppc64el with:

| gcc  -rdynamic      -Wl,-z,relro -Wl,--no-undefined -Wl,--as-needed
| -pthread -fexceptions -fgnu-runtime -o TimeMon.app/./TimeMon \
| ./obj/TimeMon.obj/loadave.c.o ./obj/TimeMon.obj/NSColorExtensions.m.o
| ./obj/TimeMon.obj/Percentages.m.o ./obj/TimeMon.obj/TimeMonColors.m.o
| ./obj/TimeMon.obj/TimeMon_main.m.o ./obj/TimeMon.obj/TimeMonWraps.m.o
| -L/usr/local/lib -L/usr/lib     -lgnustep-gui    -lgnustep-base
| -lobjc   -lm
| /usr/lib/gcc/powerpc-linux-gnu/4.9/libobjc.so: undefined reference to
| `rs6000_special_adjust_field_align_p'
| collect2: error: ld returned 1 exit status

If you look at the gcc-4.9 and gcc-4.8 build logs, there are warnings
when building libobjc:

| /«PKGBUILDDIR»/src/libobjc/encoding.c: In function
| 'objc_layout_structure_next_member':
| /«PKGBUILDDIR»/src/libobjc/encoding.c:1163:3: warning: implicit
| declaration of function 'rs6000_special_adjust_field_align_p'
| [-Wimplicit-function-declaration]
|    desired_align = ADJUST_FIELD_ALIGN (type, desired_align);
|    ^

This bug affects all GNUstep packages which now FTBFS on these
architectures.