Emulate the "TEST r/m{16,32,64}, imm{16,32,32}" instructions (opcode F7H).

This adds emulation for:
test r/m16, imm16
test r/m32, imm32
test r/m64, imm32 sign-extended to 64

OpenBSD guests compiled with clang 8.0.0 use TEST directly against a
Local APIC register instead of separate read via MOV followed by a
TEST against the register.

PR: 238794
Submitted by: jhb
Reported by: Jason Tubnor jason@tubnor.net
Tested by: Jason Tubnor jason@tubnor.net
Reviewed by: markj, Patrick Mooney patrick.mooney@joyent.com
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D20755