quad-ICE with impl Trait in binding #67166

warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
 --> src/lib.rs:1:12
  |
1 | #![feature(impl_trait_in_bindings)]
  |            ^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default

error: internal compiler error: `opaque_defn` is a local value
 --> src/lib.rs:4:9
  |
4 |   fn run(){
  |  _________^
5 | |     let _foo: Box<impl Copy + '_> = Box::new(());
6 | | }
  | |_^

error: internal compiler error: owner DefId(0:3 ~ playground[14f1]::run[0]) has no opaque type for DefId(0:4 ~ playground[14f1]::run[0]::{{opaque}}[0]) in its tables

error: internal compiler error: broken MIR in DefId(0:3 ~ playground[14f1]::run[0]) (Terminator { source_info: SourceInfo { span: src/lib.rs:5:37: 5:49, scope: scope[0] }, kind: _1 = const std::boxed::Box::<()>::new(move _2) -> [return: bb2, unwind: bb1] }): call dest mismatch (std::boxed::Box<impl std::marker::Copy> <- std::boxed::Box<()>): NoSolution
 --> src/lib.rs:5:46
  |
5 |     let _foo: Box<impl Copy + '_> = Box::new(());
  |                                              ^^

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', src/librustc_errors/lib.rs:347:17
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.41.0-nightly (5c5c8eb86 2019-12-07) running on x86_64-unknown-linux-gnu

note: compiler flags: -C opt-level=3 -C codegen-units=1 --crate-type lib

note: some of the compiler flags provided by cargo are hidden

error: could not compile `playground`.

To learn more, run the command again with --verbose.