ICE when calling member function of const generic struct with associated constant as const parameter

[DarkKirb]

I have recently been toying with const generics again and they are in a signifficantly better state than when I last used them.

Code

No special flags necessary to compile

#![feature(const_generics)]
#![feature(const_evaluatable_checked)]
pub struct SimpleStruct<const N: usize>([u8; N]);

impl<const N: usize> SimpleStruct<N> {
  pub fn new() -> Self {
    loop{}
  }
}

pub trait TraitA: Sized {
  const SIZE: usize;
  fn zero() -> Self
    where [(); Self::SIZE]:
  {
    let _: SimpleStruct<{Self::SIZE}> = SimpleStruct::<{Self::SIZE}>::new();
    loop {}
  }
}

This ICE stops occurring once you move new() out of the impl block. It happens regardless of the positioning of the zero() function.

Meta

rustc --version --verbose:

rustc 1.51.0-nightly (e22670468 2020-12-30)
binary: rustc
commit-hash: e2267046859c9ceb932abc983561d53a117089f6
commit-date: 2020-12-30
host: aarch64-unknown-linux-gnu
release: 1.51.0-nightly

also occurs on rust playground and older nightlies

Error output

error: internal compiler error: Encountered error `Unimplemented` selecting `Binder(<Self as TraitA>)` during codegen
  |
  = note: delayed at compiler/rustc_trait_selection/src/traits/codegen.rs:68:32

error: internal compiler error: ty::ConstKind::Error constructed but no error reported.
  |
  = note: delayed at /rustc/e2267046859c9ceb932abc983561d53a117089f6/compiler/rustc_middle/src/ty/consts.rs:183:43

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:974:13
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.51.0-nightly (e22670468 2020-12-30) running on aarch64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type lib

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

query stack during panic:
end of query stack
error: could not compile `testing`

Backtrace

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:974:13
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e2267046859c9ceb932abc983561d53a117089f6/library/std/src/panicking.rs:493:5
   1: std::panicking::begin_panic_fmt
             at /rustc/e2267046859c9ceb932abc983561d53a117089f6/library/std/src/panicking.rs:435:5
   2: rustc_errors::HandlerInner::flush_delayed
   3: <rustc_errors::HandlerInner as core::ops::drop::Drop>::drop
   4: core::ptr::drop_in_place
   5: <alloc::rc::Rc<T> as core::ops::drop::Drop>::drop
   6: core::ptr::drop_in_place
   7: rustc_span::with_source_map
   8: rustc_interface::interface::create_compiler_and_run
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[jyn514]

Slightly smaller:

#![feature(const_generics)]
#![feature(const_evaluatable_checked)]
pub struct SimpleStruct<const N: usize>([u8; N]);

impl<const N: usize> SimpleStruct<N> {
  pub fn new() -> Self {
    loop{}
  }
}

pub trait TraitA {
  const SIZE: usize;
  fn zero()
    where [(); Self::SIZE]:
  {
    let _ = SimpleStruct::<{Self::SIZE}>::new();
  }
}

[BoxyUwU]

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