ref: 0cb3dc37ca3d619e5f2017a592bc793094b9f7e4 dir: /libkern/getfcr-thumb.s/
TEXT setfcr(SB), $0 RET TEXT getfcr(SB), $0 RET TEXT getfsr(SB), $0 RET TEXT setfsr(SB), $0 RET