Add support for the XTENSA architecture

* configure.ac: Add XTENSA to the list of supported architectures.
* defs.h: Add XTENSA support.
* linux/xtensa/syscallent.h: New file.
* linux/xtensa/ioctlent.h.in: Likewise.
* process.c (struct_user_offsets): Add XTENSA support.
* signal.c (sys_sigreturn): Likewise.
* syscall.c (printcall, get_scno, get_syscall_args,
  get_syscall_result, get_error): Likewise.
* util.c (change_syscall): Likewise.

Signed-off-by: Chris Zankel <chris@zankel.net>
8 files changed