ICE `failed to lookup hir item during refutability checks`

[matthiaskrgr]

auto-reduced (treereduce-rust):

//@compile-flags: -frust-incomplete-and-experimental-compiler-do-not-use -frust-crate-attr=no_core
pub struct Foo {
    bar: u8,
    baa: [u32; 1],
}

const FOOMP: Foo = Foo {
    bar: 0,
    baa: [69; 1],
};

fn main() {
    let FOOMP = FOOMP;
}

original:

//@ check-pass
//@ compile-flags: -Zextra-const-ub-checks

#[repr(packed)]
pub struct Foo {
    bar: u8,
    baa: [u32; 1],
}

const FOOMP: Foo = Foo {
    bar: 0,
    baa: [69; 1],
};

fn main() {
    let FOOMP = FOOMP;
}

Version information:

c539964

Command:
/home/matthias/vcs/github/gccrs/gccrs-build/gcc/crab1 -frust-incomplete-and-experimental-compiler-do-not-use -frust-crate-attr=no_core -frust-crate-attr=feature(no_core)

Program output

crab1: internal compiler error: at mvce.rs:12:9, failed to lookup hir item during refutability checks
0x32edd17 internal_error(char const*, ...)
	../../gcc/diagnostic-global-context.cc:787
0xd0ad8a rust_be_internal_error_at(unsigned long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
	../../gcc/rust/rust-diagnostics.cc:173
0xd0ae4d rust_internal_error_at(unsigned long, char const*, ...)
	../../gcc/rust/rust-diagnostics.cc:182
0x11ac592 Rust::HIR::PathPattern::is_refutable(Rust::TyTy::BaseType const&) const
	../../gcc/rust/hir/tree/rust-hir-pattern-abstract.cc:68
0x1199a59 Rust::Analysis::PatternChecker::visit(Rust::HIR::LetStmt&)
	../../gcc/rust/checks/errors/rust-hir-pattern-analysis.cc:702
0x1199593 Rust::Analysis::PatternChecker::visit(Rust::HIR::BlockExpr&)
	../../gcc/rust/checks/errors/rust-hir-pattern-analysis.cc:281
0x119a4e3 Rust::Analysis::PatternChecker::go(Rust::HIR::Crate&)
	../../gcc/rust/checks/errors/rust-hir-pattern-analysis.cc:46
0xecc43b Rust::Session::compile_crate(char const*)
	../../gcc/rust/rust-session-manager.cc:815
/home/matthias/vcs/github/gccrs/gccrs-build/gcc/crab1 /tmp/icemaker_global_tempdir.YDWciJ2vfL70/rustc_testrunner_tmpdir_reporting.zmDxqE3hvFbC/mvce.rs -o/tmp/icemaker_global_tempdir.YDWciJ2vfL70/rustc_testrunner_tmpdir_reporting.zmDxqE3hvFbC/binaryname -frust-incomplete-and-experimental-compiler-do-not-use -frust-crate-attr=no_core -frust-crate-attr=feature(no_core)
Please submit a full bug report, with preprocessed source (by using -freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.