[patch]: Software single-stepping on ARMs

[Richard Earnshaw]

This patch enables support for software single-stepping on ARM processors.  This is required for NetBSD, and a good idea on some older linux kernels, where single-stepping tended to work erratically.

<date> Richard Earnshaw <rearnsha@arm.com>

	* arm-tdep.c (arm_software_single_step): New function.
	(arm_get_next_pc, thumb_get_next_pc, bitcount, shifted_reg_val): Only
	needed for software single-stepping.