* inf-ptrace.h: Update copyright year. Sync comment with

* inf-ptrace.h: Update copyright year.  Sync comment with
inf-ptrace.c.
(inf_ptrace_trad_target): New prototype.
* inf-ptrace.c: Update copyright year.  Include "regcache.h" and
"gdb_assert.h"
(inf_ptrace_target): Add comment.
(inf_ptrace+register_u_offset): New variable.
(inf_ptrace_fetch_register, inf_ptrace_fetch_registers)
(inf_ptrace_store_register, inf_ptrace_store_registers)
(inf_ptrace_trad_target): New functions.
* Makefile.in (inf-ptrace.o): Update dependencies.