Fixup some includes for macOS

src/decomp/include/PR/os_libc.h

@@ -3,8 +3,13 @@
 
 #include "ultratypes.h"
 
+// These are defined in macOS (BSD?), so we want to def them out.
+#ifndef __APPLE__
+
 // Old deprecated functions from strings.h, replaced by memcpy/memset.
 extern void bcopy(const void *, void *, size_t);
 extern void bzero(void *, size_t);
 
+#endif
+
 #endif /* !_OS_LIBC_H_ */