windows building issues compat.h / unistd.h

[imtrynalearn]

  CC     sgminer-sgminer.o
In file included from sgminer.c:52:0:
compat.h:76:19: error: conflicting types for 'sleep'
 static inline int sleep(unsigned int secs)
                   ^~~~~
In file included from sgminer.c:24:0:
c:\mingw\include\unistd.h:117:10: note: previous definition of 'sleep' was here
 unsigned sleep( unsigned period ){ return __mingw_sleep( period, 0 ); }
          ^~~~~