delegation: OOM

I tried this code:

#![feature(fn_delegation)]
trait Trait<T> {
    fn foo<U>(&self, _: dyn Trait) {}
}

reuse Trait::<_>::foo::<i32> as x;

fn main() {}

I expected to see this happen:
no oom

Instead, this happened:
oom

Meta

rustc --version --verbose:

rustc 1.96.0-nightly (a87c9b960 2026-04-09)
binary: rustc
commit-hash: a87c9b96031d4d8698bb0cd6533e83bc6d77ddaa
commit-date: 2026-04-09
host: x86_64-unknown-linux-gnu
release: 1.96.0-nightly
LLVM version: 22.1.2

   8,68%  librustc_driver-5ecf1647954ff888.so             [.] rustc_query_impl::execution::collect_active_query_jobs
   4,59%  librustc_driver-5ecf1647954ff888.so             [.] rustc_query_impl::execution::collect_active_query_jobs_inner::<rustc_middle::query::caches::DefIdCache<rustc_middle::query::erase::ErasedData<[u8; 16]>>>
   3,57%  librustc_driver-5ecf1647954ff888.so             [.] rustc_query_impl::execution::collect_active_query_jobs_inner::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 0]>, rustc_middle::dep_graph::graph::DepNodeIndex>>

Start by compiling the supplied fn_delegation reproducer with the reported nightly compiler and confirm the out-of-memory behavior. Use the included query-job backtrace as the initial investigation lead; done means the reproducer no longer exhausts memory without regressing delegation behavior.