Enum with const generic generates "'no errors encountered even though delay_span_bug issued"

[dignifiedquire]

Code

pub enum Foo<const A: usize> {
    Bar,
    Baz([(); A]),
}


fn main() {
    // Cannot infer type for 9
    // let x = Foo::Bar::<9>;
    // Compiler error 
    let x = Foo::Bar::<9usize>;
}

Playground: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=555bd63340732916af008758d6acedff

Meta

rustc --version --verbose:

rustc 1.53.0 (53cb7b09b 2021-06-17) running on x86_64-unknown-linux-gnu

Error output

   Compiling playground v0.0.1 (/playground)
warning: unused variable: `x`
  --> src/main.rs:11:9
   |
11 |     let x = Foo::Bar::<9usize>;
   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: 1 warning emitted

error: internal compiler error: unexpected const parent in type_of_def_id(): Expr(Expr { hir_id: HirId { owner: DefId(0:11 ~ playground[21c2]::main), local_id: 5 }, kind: Path(Resolved(None, Path { span: src/main.rs:11:13: 11:31 (#0), res: Def(Ctor(Variant, Const), DefId(0:6 ~ playground[21c2]::Foo::Bar::{constructor#0})), segments: [PathSegment { ident: Foo#0, hir_id: Some(HirId { owner: DefId(0:11 ~ playground[21c2]::main), local_id: 1 }), res: Some(Def(Enum, DefId(0:3 ~ playground[21c2]::Foo))), args: None, infer_args: true }, PathSegment { ident: Bar#0, hir_id: Some(HirId { owner: DefId(0:11 ~ playground[21c2]::main), local_id: 4 }), res: Some(Err), args: Some(GenericArgs { args: [Const(ConstArg { value: AnonConst { hir_id: HirId { owner: DefId(0:11 ~ playground[21c2]::main), local_id: 2 }, body: BodyId { hir_id: HirId { owner: DefId(0:11 ~ playground[21c2]::main), local_id: 3 } } }, span: src/main.rs:11:24: 11:30 (#0) })], bindings: [], parenthesized: false }), infer_args: false }] })), span: src/main.rs:11:13: 11:31 (#0) })
  |
  = note: delayed at compiler/rustc_typeck/src/collect/type_of.rs:474:26

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at /rustc/53cb7b09b00cbea8754ffb78e7e3cb521cb8af4b/compiler/rustc_trait_selection/src/opaque_types.rs:1007:32

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_typeck/src/check/coercion.rs:154:49

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_mir_build/src/build/mod.rs:747:18

error: internal compiler error: mir_const_qualif: MIR had errors
  --> src/main.rs:11:24
   |
11 |     let x = Foo::Bar::<9usize>;
   |                        ^^^^^^
   |
   = note: delayed at compiler/rustc_mir/src/transform/mod.rs:237:18

error: internal compiler error: PromoteTemps: MIR had errors
  --> src/main.rs:11:24
   |
11 |     let x = Foo::Bar::<9usize>;
   |                        ^^^^^^
   |
   = note: delayed at compiler/rustc_mir/src/transform/promote_consts.rs:55:22

error: internal compiler error: broken MIR in DefId(0:12 ~ playground[21c2]::main::{constant#0}) ("return type"): bad type [type error]
  --> src/main.rs:11:24
   |
11 |     let x = Foo::Bar::<9usize>;
   |                        ^^^^^^
   |
   = note: delayed at compiler/rustc_mir/src/borrow_check/type_check/mod.rs:252:27

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_mir/src/borrow_check/type_check/mod.rs:721:20

error: internal compiler error: broken MIR in DefId(0:12 ~ playground[21c2]::main::{constant#0}) (LocalDecl { mutability: Mut, local_info: None, internal: false, is_block_tail: None, ty: [type error], user_ty: None, source_info: SourceInfo { span: src/main.rs:11:24: 11:30 (#0), scope: scope[0] } }): bad type [type error]
  --> src/main.rs:11:24
   |
11 |     let x = Foo::Bar::<9usize>;
   |                        ^^^^^^
   |
   = note: delayed at compiler/rustc_mir/src/borrow_check/type_check/mod.rs:252:27

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:1018:13
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 1.53.0 (53cb7b09b 2021-06-17) running on x86_64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2 --crate-type bin

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

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

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