Revert "OS-8005 bhyve memory pressure needs to target ARC better (#354)"
This reverts commit a6033573eedd94118d2b9e65f45deca0bf4b42f7.

@@ -1940,18 +1940,10 @@
         }
 
         return (0);
 }
 
-int
-vm_arc_resv(struct vmctx *ctx, size_t len)
-{
-        if (ioctl(ctx->fd, VM_ARC_RESV, (uint64_t)len) != 0) {
-                return (errno);
-        }
-        return (0);
-}
 #endif /* __FreeBSD__ */
 
 #ifdef __FreeBSD__
 const cap_ioctl_t *
 vm_get_ioctls(size_t *len)