ICE when accessing value on a enum variant

[bombless]

#![feature(associated_consts)]

trait Foo {
    const X: u8 = 42;
    fn test();
}

enum Bar {
    X
}

impl Foo for Bar {
    fn test() {
        println!("{}", Self::X);
    }
}

fn main() {
    Bar::X::test();
}

https://is.gd/uL2NUM

rustc 1.16.0-nightly (7e38a89a7 2017-01-06)
error: internal compiler error: /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/librustc_typeck/astconv.rs:1516: unexpected definition: Variant(DefId { krate: CrateNum(0), node: DefIndex(8) => rust_out/4089d7c8b778d88cec885baf7b69e6df-exe::Bar[0]::X[0] })
  �(B�[m--> <anon>:19:5�(B�[m
   �(B�[m|
19 �(B�[m|     Bar::X::test();�(B�[m
   �(B�[m|     �(B�[m^^^^^^^^^^^^

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

thread 'rustc' panicked at 'Box<Any>', /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/librustc_errors/lib.rs:382
note: Run with `RUST_BACKTRACE=1` for a backtrace.

[bombless]

Seems that the real issue is about accessing a value on a enum variant.

enum Bar {
    X
}


fn main() {
    Bar::X::test;
}

The ICE is only triggered on nightly, no feature-gate required.

[petrochenkov]

Duplicate of #38862, fixed in #38925