bpf: add xBPF ISA

bpf: add xBPF ISA

This patch adds support for xBPF, another ISA targetting the BPF
virtual architecture. For now, the primary difference between eBPF
and xBPF is that xBPF supports indirect calls through the
'call %reg' form of the call instruction.

bfd/
	* archures.c (bfd_mach_xbpf): Define.
	* bfd-in2.h: Regenerate.
	* cpu-bpf.c (bfd_xbpf_arch) New.
	(bfd_bpf_arch) Update next in list field to point to xbpf arch.

cpu/
	* bpf.cpu (arch bpf): Add xbpf mach and isas.
	(define-xbpf-isa) New pmacro.
	(all-isas) Add xbpfle,xbpfbe.
	(endian-isas): New pmacro.
	(mach xbpf): New.
	(model xbpf-def): Likewise.
	(h-gpr): Add xbpf mach.
	(f-dstle, f-srcle, dstle, srcle): Add xbpfle isa.
	(f-dstbe, f-srcbe, dstbe, srcbe): Add xbpfbe isa.
	(define-alu-insn-un): Use new endian-isas pmacro.
	(define-alu-insn-bin, define-alu-insn-mov): Likewise.
	(define-endian-insn, define-lddw): Likewise.
	(dlind, dxli, dxsi, dsti): Likewise.
	(define-cond-jump-insn, define-call-insn): Likewise.
	(define-atomic-insns): Likewise.

gas/
	* config/tc-bpf.c: Add option -mxbpf to select xbpf isa.
	* testsuite/gas/bpf/indcall-1.d: New file.
	* testsuite/gas/bpf/indcall-1.s: Likewise.
	* testsuite/gas/bpf/indcall-bad-1.l: Likewise.
	* testsuite/gas/bpf/indcall-bad-1.s: Likewise.
	* testsuite/gas/bpf/bpf.exp: Run new tests.

opcodes/
	* bpf-desc.c: Regenerate.
	* bpf-desc.h: Likewise.
	* bpf-opc.c: Likewise.
	* bpf-opc.h: Likewise.
	* disassemble.c (disassemble_init_for_target): Set bits for xBPF
	ISA when appropriate.