ref: 2d06aac2abbd22757b6aa33b4fdc0c9ead4b7d50 dir: /sys/src/libc/arm/getfcr.s/
TEXT setfcr(SB), $0 RET TEXT getfcr(SB), $0 RET TEXT getfsr(SB), $0 RET TEXT setfsr(SB), $0 RET