ICE on generic trait impl for aliased array type

[TechPriest]

Following snippet is sufficient to trigger an ICE on both stable 1.32 and nightly 1.34

use std::io::Read;
use std::default::Default;

trait MyRead: Sized {
    fn read<R: Read>(r: &mut R) -> Self;
}

type Foobar = [u8;10];

impl MyRead for Foobar {
    fn read<R: Read>(r: &mut R) -> Self {
        let mut result: Self = Default::default();
        r.read(&mut result[..]).unwrap();
        result
    }
}

fn main() {
}

Meta

rustc 1.32.0 (9fda7c2 2019-01-16) running on x86_64-pc-windows-msvc

Backtrace:

    Checking rs_repro1 v0.1.0 (D:\Work\src\test\rs_repro1)
     Running `rustc --edition=2018 --crate-name rs_repro1 src\main.rs --color always --crate-type bin --emit=dep-info,metadata -C debuginfo=2 -C metadata=1fc4b6d5a86da623 -C extra-filename=-1fc4b6d5a86da623 --out-dir D:\Work\src\test\rs_repro1\target\debug\deps -C incremental=D:\Work\src\test\rs_repro1\target\debug\incremental -L dependency=D:\Work\src\test\rs_repro1\target\debug\deps`
error: internal compiler error: src\librustc\ty\sty.rs:2107: expected constant usize, got Const {
    ty: usize,
    val: Unevaluated(
        DefId(0/1:10 ~ rs_repro1[b69e]::Foobar[0]::{{constant}}[0]),
        []
    )
}

thread 'main' panicked at 'Box<Any>', src\librustc_errors\lib.rs:600:9
stack backtrace:
   0: std::sys_common::alloc::realloc_fallback
   1: std::panicking::take_hook
   2: std::panicking::take_hook
   3: <rustc::ty::sty::Binder<rustc::ty::ProjectionPredicate<'tcx>> as rustc::ty::ToPredicate<'tcx>>::to_predicate
   4: std::panicking::rust_panic_with_hook
   5: <rustc_errors::diagnostic::SubDiagnostic as core::fmt::Debug>::fmt
   6: rustc_errors::Handler::bug
   7: rustc::util::ppaux::get_highlight_region_for_bound_region
   8: rustc::util::ppaux::verbose
   9: rustc::ty::context::tls::track_diagnostic
  10: rustc::util::ppaux::verbose
  11: rustc::util::bug::bug_fmt
  12: rustc::util::bug::bug_fmt
  13: <rustc_mir::util::liveness::IdentityMap<'a, 'tcx> as core::fmt::Debug>::fmt
  14: <rustc_mir::transform::qualify_consts::Qualifier<'a, 'tcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_rvalue
  15: <rustc_mir::transform::qualify_consts::Qualifier<'a, 'tcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_assign
  16: <rustc_mir::transform::qualify_consts::QualifyAndPromoteConstants as rustc_mir::transform::MirPass>::run_pass
  17: rustc_mir::transform::run_passes
  18: rustc_mir::transform::run_passes
  19: rustc_mir::transform::run_passes
  20: <rustc::traits::query::NoSolution as core::fmt::Debug>::fmt
  21: rustc::ty::context::tls::track_diagnostic
  22: rustc::dep_graph::graph::DepGraph::assert_ignored
  23: <rustc::traits::query::type_op::subtype::Subtype<'tcx> as rustc::traits::query::type_op::QueryTypeOp<'gcx, 'tcx>>::perform_query
  24: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::try_print_query_stack
  25: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::try_print_query_stack
  26: rustc::ty::query::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_validated
  27: <rustc::mir::Location as rustc_mir::borrow_check::nll::type_check::NormalizeLocation>::to_locations
  28: <rustc::traits::query::NoSolution as core::fmt::Debug>::fmt
  29: <rustc::traits::query::NoSolution as core::fmt::Debug>::fmt
  30: rustc::ty::context::tls::track_diagnostic
  31: rustc::dep_graph::graph::DepGraph::assert_ignored
  32: <rustc::traits::query::type_op::subtype::Subtype<'tcx> as rustc::traits::query::type_op::QueryTypeOp<'gcx, 'tcx>>::perform_query
  33: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::try_print_query_stack
  34: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::try_print_query_stack
  35: rustc::ty::query::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_borrowck
  36: <rustc_driver::pretty::UserIdentifiedItem as core::fmt::Debug>::fmt
  37: <rustc_driver::pretty::UserIdentifiedItem as core::fmt::Debug>::fmt
  38: <rustc_driver::pretty::UserIdentifiedItem as core::fmt::Debug>::fmt
  39: <rustc_driver::pretty::UserIdentifiedItem as core::fmt::Debug>::fmt
  40: rustc_driver::driver::compile_input
  41: rustc_driver::run_compiler
  42: <rustc_driver::profile::trace::Query as core::fmt::Debug>::fmt
  43: rustc_driver::run_compiler
  44: <humantime::duration::Error as std::error::Error>::cause
  45: _rust_maybe_catch_panic
  46: rustc_driver::profile::dump
  47: rustc_driver::main
  48: <unknown>
  49: std::panicking::update_panic_count
  50: _rust_maybe_catch_panic
  51: std::rt::lang_start_internal
  52: <unknown>
  53: <unknown>
  54: BaseThreadInitThunk
  55: RtlUserThreadStart
query stack during panic:
#0 [mir_validated] processing `<[u8; _] as MyRead>::read`
#1 [mir_borrowck] processing `<[u8; _] as MyRead>::read`
end of query stack
error: aborting due to previous error


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 (9fda7c223 2019-01-16) running on x86_64-pc-windows-msvc

note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin

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

error: Could not compile `rs_repro1`.

Caused by:
  process didn't exit successfully: `rustc --edition=2018 --crate-name rs_repro1 src\main.rs --color always --crate-type bin --emit=dep-info,metadata -C debuginfo=2 -C metadata=1fc4b6d5a86da623 -C extra-filename=-1fc4b6d5a86da623 --out-dir D:\Work\src\test\rs_repro1\target\debug\deps -C incremental=D:\Work\src\test\rs_repro1\target\debug\incremental -L dependency=D:\Work\src\test\rs_repro1\target\debug\deps` (exit code: 101)```

[hellow554]

Minified it a little bit. If one remove the : Self it does not ICE.

use std::io::{empty, Read};

trait Foo {
    fn foo();
}

impl Foo for [u8; 10] {
    fn foo() {
        let mut result: Self = [0; 10];
        empty().read(&mut result).unwrap();
    }
}

[hellow554]

The bug also happens on beta (of course).
Nightly-2017-09-01 does not ICE, nightly-2017-10-01 does. But I'm not sure if that's the same error. Let me know if I should bisect that further.

env RUST_BACKTRACE=1 cargo build
   Compiling foo v0.1.0 (file:///tmp/tmp.LgU9STqlid/foo)
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 1.22.0-nightly (c6884b12d 2017-09-30) running on x86_64-unknown-linux-gnu

note: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:335:20
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at /checkout/src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at /checkout/src/libstd/sys_common/backtrace.rs:60
             at /checkout/src/libstd/panicking.rs:381
   3: std::panicking::default_hook
             at /checkout/src/libstd/panicking.rs:391
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:577
   5: std::panicking::begin_panic
             at /checkout/src/libstd/panicking.rs:538
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:522
   7: rust_begin_unwind
             at /checkout/src/libstd/panicking.rs:498
   8: core::panicking::panic_fmt
             at /checkout/src/libcore/panicking.rs:71
   9: core::panicking::panic
             at /checkout/src/libcore/panicking.rs:51
  10: <rustc_mir::transform::qualify_consts::Qualifier<'a, 'tcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_rvalue
  11: <rustc_mir::transform::qualify_consts::Qualifier<'a, 'tcx, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_assign
  12: rustc::mir::visit::Visitor::visit_basic_block_data
  13: <rustc_mir::transform::qualify_consts::QualifyAndPromoteConstants as rustc::mir::transform::MirPass>::run_pass
  14: rustc_mir::transform::run_suite
  15: rustc_mir::transform::mir_validated
  16: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_validated<'tcx>>::try_get_with::{{closure}}::{{closure}}::run_provider
  17: rustc::dep_graph::graph::DepGraph::with_task
  18: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_validated<'tcx>>::try_get
  19: rustc::ty::maps::TyCtxtAt::mir_validated
  20: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_validated
  21: rustc_borrowck::borrowck::borrowck
  22: rustc::ty::maps::<impl rustc::ty::maps::queries::borrowck<'tcx>>::try_get_with::{{closure}}::{{closure}}::run_provider
  23: rustc::dep_graph::graph::DepGraph::with_task
  24: rustc::ty::maps::<impl rustc::ty::maps::queries::borrowck<'tcx>>::try_get
  25: rustc::ty::maps::TyCtxtAt::borrowck
  26: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::borrowck
  27: rustc_borrowck::borrowck::check_crate
  28: rustc::ty::context::TyCtxt::create_and_enter
  29: rustc_driver::driver::compile_input
  30: rustc_driver::run_compiler

[arielb1]

cc @oli-obk

[hellow554]

Possible dup of #57796