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

@@ -1580,17 +1580,10 @@
                 memflags |= VM_MEM_F_INCORE;
         vm_set_memflags(ctx, memflags);
 #ifdef  __FreeBSD__
         err = vm_setup_memory(ctx, memsize, VM_MMAP_ALL);
 #else
-        err = vm_arc_resv(ctx, memsize);
-        if (err != 0) {
-                (void) fprintf(stderr, "Could not shrink ARC: %s\n",
-                    strerror(err));
-                exit(4);
-        }
-
         do {
                 errno = 0;
                 err = vm_setup_memory(ctx, memsize, VM_MMAP_ALL);
                 error = errno;
                 if (err != 0 && error == ENOMEM) {