ICE on miri check: self.meta.is_none()

[earthengine]

In a recent test for #28796 the following code

#![feature(unsized_locals)]
fn a(f: Box<dyn FnOnce()>) { f() }

fn main() {
    let f = ||{ println!("Hello!") };
    a(Box::new(f))
}

Playground

can compile and can run in the playground, but the Miri check tool gives

   Compiling playground v0.0.1 (/playground)
thread 'main' panicked at 'assertion failed: self.meta.is_none()', librustc_mir/interpret/place.rs:142:9
note: Run with `RUST_BACKTRACE=1` for 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 1.32.0-nightly (13dab66a6 2018-11-05) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z always-encode-mir -Z mir-emit-retag -Z mir-opt-level=0 -C codegen-units=1 -C debuginfo=2 --crate-type bin

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.