conformtest: XFAIL uc_mcontext test for powerpc32 (bug 21635).
This patch XFAILs one test where the powerpc32 ucontext_t has the
wrong type of a field, to allow the conform/ tests as a whole to pass
once the namespace issues are fixed.
Tested with build-many-glibcs.py.
[BZ #21635]
* sysdeps/unix/sysv/linux/powerpc/powerpc32/Makefile
[$(subdir) = conform] (conformtest-xfail-conds): New variable.
* conform/data/signal.h-data (uc_mcontext): XFAIL for
powerpc32-linux.
* conform/data/ucontext.h-data (uc_mcontext): Likewise.