MOVQ AX, CR0 // 0f22c0
	MOVQ DX, CR0 // 0f22c2
	MOVQ DI, CR4 // 0f22e7
	MOVQ DR0, AX // 0f21c0
	MOVQ DR6, DX // 0f21f2
	MOVQ DR7, SI // 0f21fe
	// Test other movtab entries.
	PUSHQ GS // 0fa8
	PUSHQ FS // 0fa0
	POPQ FS  // 0fa1
	POPQ GS  // 0fa9
	// All instructions below semantically have unsigned operands,
	// but previous assembler permitted negative arguments.