This patch updates ptrace.c to support multithread debugging.  So far, only
one breakpoint's location was kept by kernel, however, in the multithreaded
application's debug, it is required to kept multi-point breakpoint locations
by kernel.

In this implementation, maximum number of MAX_TRAPS(=10 (by default))
breakpoint's information will be kept in the "debug_trap" member of the
thread_struct for each thread.

	* include/asm-m32r/processor.h: 
	  Modify debug_trap struct to keep multipoint breakpoint locations
	  for multithread debugging.

	* arch/m32r/kernel/ptrace.c:
	- Update to support multithread debugging.
	- Remove unused functions, withdraw_debug_trap_for_signal() and
	  embed_debug_trap_for_signal().
Signed-off-by: Kei Sakamoto <ksakamot@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>