* arm-xdep.c: Move native-specific code to here from arm-tdep.c.

	* arm-xdep.c: Move native-specific code to here from arm-tdep.c.
	* arm-tdep.c (arm_apcs_32): New global.
	(arm_addr_bits_remove, arm_saved_pc_after_call,
 	arm_push_dummy_frame, arm_pop_frame): New functions.
	(arm_skip_prologue): Updated version from Richard Earnshaw.
	(_initialize_arm_tdep): Add set/show "apcs32".
	* config/arm/tm-arm.h (ADDR_BITS_REMOVE): Call
	arm_addr_bits_remove.
	(SAVED_PC_AFTER_CALL): Call arm_saved_pc_after_call.
	(frame_find_saved_regs): Declare properly.
	(PUSH_DUMMY_FRAME): Call arm_push_dummy_frame.
	(POP_FRAME): Call arm_pop_frame, use ADDR_BITS_REMOVE instead of
	explicit mask.
	* config/arm/nm-arm.h: New file.
	* config/arm/xm-arm.h (KERNEL_U_ADDR, FETCH_INFERIOR_REGISTERS):
	Move definitions to nm-arm.h.
	* config/arm/arm.mh (NAT_FILE): Define.