[perl #132349] $*IN.getc not blocking on macOS

[Pawel Pabian via RT]

There is no strace on macOS, I used dtruss (dtrace):

$ dtruss -p 1827
SYSCALL(args)            = return
fstat64(0x0, 0x7FFF5B18B2F0, 0x1)                = 0 0
lseek(0x0, 0x0, 0x1)             = 54132 0
write(0x1, "Nil\n\0", 0x4)               = 4 0
thread_selfid(0x0, 0x7F8252ED2090, 0x4)          = 24710 0