* dst.h, dstread.c, config/m68k/{apollo68b.mt,tm-apollo68b.h}:
New files.
* config/m68k/nm-apollo68b.h: Add more defines.
* configure.in: Recognize apollo target, not just host.
* exec.c (ignore): Return 0.
* stack.c (return_command): Fetch lazy value directly, not via
VALUE_CONTENTS, to avoid "value computed is not used".
* inflow.c (new_tty): Move osigttou inside #if.
* remote.c (remote_fetch_registers): If remote reply is short, just
note that fact and keep going (reading extra registers as all bits 0).
(remote_store_registers): Send number of registers that were found
by remote_fetch_registers.
* m68k-tdep.c, config/m68k/tm-m68k.h, config/m68k/tm-*.h: Remove
HAVE_68881. Define CANNOT_STORE_REGISTER if ptrace() can't write
floating registers.
* config/m68k/{tm-m68k-nofp.h,m68k-nofp.mt,tm-m68k-fp.h,m68k-fp.mt}:
Remove, replaced by {tm-m68k-em.h,m68k-em.mt}.
* Makefile.in, configure.in: Change accordingly.
