New gdbarch methods breakpoint_kind_from_pc and sw_breakpoint_from_kind

New gdbarch methods breakpoint_kind_from_pc and sw_breakpoint_from_kind

This patch adds two gdbarch methods breakpoint_kind_from_pc and
sw_breakpoint_from_kind, and uses target_info.placed_size as "kind"
of the breakpoint.  This patch updates the usages of
target_info.placed_size.

The "kind" of a breakpoint is determined by gdbarch rather than
target, so we have gdbarch method breakpoint_kind_from_pc, and we
should set target_info.placed_size out of each implementation of
target to_insert_breakpoint.  In this way, each target doesn't have
to set target_info.placed_size any more.

This patch also sets target_info.placed_address before
target_insert_breakpoint too, so that target to_insert_breakpoint
can use it, see record_full_insert_breakpoint.

Before we call target_insert_breakpoint, we set
target_info.placed_address and target_info.placed_size like this,

      CORE_ADDR addr = bl->target_info.reqstd_address;

      bl->target_info.placed_size = gdbarch_breakpoint_kind_from_pc (bl->gdbarch, &addr);
      bl->target_info.placed_address = addr;

      return target_insert_breakpoint (bl->gdbarch, &bl->target_info);

target_insert_breakpoint may fail, but it doesn't matter to the "kind"
and "placed_address" of a breakpoint.  They should be determined by
gdbarch.

gdb:

2016-11-03  Yao Qi  <yao.qi@linaro.org>

	* arch-utils.h (GDBARCH_BREAKPOINT_MANIPULATION): Define
	breakpoint_kind_from_pc and sw_breakpoint_from_kind.
	(GDBARCH_BREAKPOINT_MANIPULATION_ENDIAN): Likewise.
	(SET_GDBARCH_BREAKPOINT_MANIPULATION): Call
	set_gdbarch_breakpoint_kind_from_pc and
	set_gdbarch_sw_breakpoint_from_kind.
	* arm-tdep.c: Add comments.
	* bfin-tdep.c: Likewise.
	* breakpoint.c (breakpoint_kind): New function.
	(insert_bp_location): Set target_info.placed_size and
	target_info.placed_address.
	(bkpt_insert_location): Likewise.
	* cris-tdep.c: Add comments.
	* gdbarch.sh (breakpoint_kind_from_pc): New.
	(sw_breakpoint_from_kind): New.
	* gdbarch.c, gdbarch.h: Regenerated.
	* ia64-tdep.c (ia64_memory_insert_breakpoint): Don't set
	bp_tgt->placed_size.
	(ia64_memory_remove_breakpoint): Don't assert
	bp_tgt->placed_size.
	(ia64_breakpoint_kind_from_pc): New function.
	(ia64_gdbarch_init): Install ia64_breakpoint_kind_from_pc.
	* m32r-tdep.c (m32r_memory_insert_breakpoint): Don't set
	bp_tgt->placed_size.
	* mem-break.c (default_memory_insert_breakpoint): Don't set
	bp_tgt->placed_size.  Call gdbarch_sw_breakpoint_from_kind.
	(default_memory_remove_breakpoint): Call
	gdbarch_sw_breakpoint_from_kind.
	(memory_validate_breakpoint): Don't check bp_tgt->placed_size.
	* mips-tdep.c: Add comments.
	* mt-tdep.c: Likewise.
	* nios2-tdep.c: Likewise.
	* record-full.c (record_full_insert_breakpoint): Don't call
	gdbarch_breakpoint_from_pc.  Don't set bp_tgt->placed_address
	and bp_tgt->placed_size.
	* remote.c (remote_insert_breakpoint): Don't call
	gdbarch_remote_breakpoint_from_pc.  Use bp_tgt->placed_size.
	Don't set bp_tgt->placed_address and bp_tgt->placed_size.
	(remote_insert_hw_breakpoint): Likewise.
	* score-tdep.c: Likewise.
	* sh-tdep.c: Likewise.
	* tic6x-tdep.c: Likewise.
	* v850-tdep.c: Likewise.
	* xtensa-tdep.c: Likewise.