gdbarch software_single_step frame_info to regcache: aarch64

Use regcache in software_single_step.

gdb:

2016-11-22  Yao Qi  <yao.qi@linaro.org>

	* aarch64-tdep.c (aarch64_software_single_step): Call
	get_regcache_arch instead of get_frame_arch.  Call
	regcache_read_pc instead of get_frame_pc.
2 files changed