GCCRS fails to handle deeply nested Option types and gets killed by SIGKILL instead of emitting proper trait error

Summary

When compiling the attached Rust code with GCCRS, the compiler gets terminated with SIGKILL due to processing time exceeded, while rustc correctly reports the missing Display trait implementation. This indicates a defect in GCCRS's handling of deeply nested types and trait checking.

Reproducer

I tried this code:

pub fn foo() -> impl std::fmt::Display {
    Some(Some(Some(/* ... 39 layers of Some nesting ... */)))
}

fn main() {}

Does the code make use of any (1.49) nightly feature ?

• Nightly

Godbolt link

https://godbolt.org/z/n6f1WoeWb

Actual behavior

Compiler process gets killed:
Killed - processing time exceeded
Program terminated with signal: SIGKILL

Expected behavior

The compiler should emit a proper trait implementation error.

GCC Version

14.2

Start with the 39-layer nested Option reproducer from the issue and compare GCCRS with rustc using the linked Godbolt example. Trace the trait-checking path involved in processing the nested types; done means GCCRS emits a proper missing Display trait error instead of being killed by SIGKILL.