* configure.host: Add x86_64-*-freebsd*.

* configure.host: Add x86_64-*-freebsd*.
* configure.tgt: Add x86_64-*-freebsd*.
* Makefile.in (amd64fbsd-nat.o, amd64fbsd-tdep.o): New targets.
* x86-64-tdep.h (amd64fbsd_sigtramp_start, amd64fbsd_sigtramp_end,
amd64fbsd_sc_reg_offset): Add extern declarations.
(X86_64_RAX_REGNUM, X86_64_RDX_REGNUM, X86_64_RDI_REGNUM,
X86_64_RBP_REGNUM, X86_64_RSP_REGNUM, X86_64_RIP_REGNUM,
X86_64_EFLAGS_REGNUM, X86_64_ST0_REGNUM, X86_64_XMM0_REGNUM,
X86_64_XMM1_REGNUM): Moved here ...
* x86-64-tdep.c: ... from here.
* amd64fbsd-nat.c: New file.
* amd64fbsd-tdep.c: New file.
* config/i386/nm-fbsd64.h: New file.
* config/i386/fbsd64.mh: New file.
* config/i386/fbsd64.mt: New file.