(altos_skip_prologue, delta68_frame_saved_pc, isi_frame_num_args)
(delta68_frame_num_args, news_frame_num_args, m68k_skip_prologue)
(m68k_frame_init_saved_regs, m68k_saved_pc_after_call): Use
read_memory_unsigned_integer instead of read_memory_integer when
dealing with addresses and instruction opcodes.
* m68klinux-tdep.c (m68k_linux_sigtramp_saved_pc)
(m68k_linux_frame_saved_pc): Likewise.