@------------------------------------------------------------------------------
isb sy
isb
+ isb #15
+ isb #1
@ CHECK: isb sy @ encoding: [0xbf,0xf3,0x6f,0x8f]
@ CHECK: isb sy @ encoding: [0xbf,0xf3,0x6f,0x8f]
+@ CHECK: isb sy @ encoding: [0xbf,0xf3,0x6f,0x8f]
+@ CHECK: isb #0x1 @ encoding: [0xbf,0xf3,0x61,0x8f]
@------------------------------------------------------------------------------