func emitRbrac(asm *amd64.Assembler, cc *compiled) {
header := cc.stack[len(cc.stack)-1]
cc.stack = cc.stack[:len(cc.stack)-1]
asm.JmpRel(gojit.Addr(asm.Buf[header:]))
end := asm.Off
asm.Off = header
asm.Testb(amd64.Imm{0xff}, amd64.Indirect{amd64.Rax, 0, 8})
asm.JccRel(amd64.CC_Z, gojit.Addr(asm.Buf[end:]))
asm.Off = end
}