Turn tcx.vtable_allocation() into a query.

compiler/rustc_middle/src/ty/mod.rs

@@ -2050,6 +2050,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
         trait_impls_of: trait_def::trait_impls_of_provider,
         type_uninhabited_from: inhabitedness::type_uninhabited_from,
         const_param_default: consts::const_param_default,
+        vtable_allocation: vtable::vtable_allocation_provider,
         ..*providers
     };
 }