message: Make vtable_allocation always succeed
diff: @@ -72,10 +72,7 @@ pub(crate) fn get_vtable<'tcx>(
  let vtable_ptr = if let Some(vtable_ptr) = fx.vtables.get(&(ty, trait_ref)) {
  *vtable_ptr
  } else {
  - let vtable_alloc_id = match fx.tcx.vtable_allocation(ty, trait_ref) {
  - Ok(alloc) => alloc,
  - Err(_) => fx.tcx.sess.fatal("allocation of constant vtable failed"),
  - };
  + let vtable_alloc_id = fx.tcx.vtable_allocation(ty, trait_ref);
  let vtable_allocation = fx.tcx.global_alloc(vtable_alloc_id).unwrap_memory();
  let vtable_ptr = pointer_for_allocation(fx, vtable_allocation);
  