GDB 5.0 won't build on GNU/Linux/sparc

[Alexandre Oliva]

gdb/sparc-tdep.c contains code in supply_gregset() and fill_gregset()
that will only compile on Solaris/sparc.  glibc doesn't define
prgreg_t, R_I7, R_PS, R_PC, R_nPC nor R_Y.  In fact, registers from i0
to i7 aren't even available in glibc's gregset.  The solution is to
disable USE_PROC_FS, which can be accomplished by #including the
generic config/nm-linux.h from config/sparc/nm-linux.h, as all other
architecture-specific `nm-linux.h's do (actually, it's also missing
from config/powerpc/nm-linux.h).  Unfortunately, I don't have access to a
GNU/Linux/powerpc platform to test the second change.  On
GNU/Linux/sparc, it builds correctly, but it still doesn't work :-(
child_resume is called with step==1, and aborts because
SOFTWARE_SINGLE_STEP_P is also 1.  I'm investigating.  Meanwhile, ok
to install?  Release branch?