need local prototype to make things happy

libc/sysdeps/linux/common/mremap.c

@@ -13,6 +13,8 @@
 #include <sys/mman.h>
 #undef mremap
 
+void *mremap(void *, size_t, size_t, int, void *);
+
 libc_hidden_proto(mremap)
 _syscall5(void *, mremap, void *, old_address, size_t, old_size, size_t,
 		  new_size, int, may_move, void *, new_address);