ices/67684.sh: fixed with no errors

[github-actions]

Issue: rust-lang/rust#67684

#!/bin/bash

rustc - << 'EOF'
#![crate_type = "lib"]
trait ParseError {
    type StreamError;
}
impl<T> ParseError for T {
    type StreamError = ();
}
trait Stream {
    type Error;
}
trait Parser
where
    <Self as Parser>::PartialState: Default,
{
    type PartialState;
    fn parse_mode(&Self, Self::PartialState) {}
}
struct AndThen<A, B>(core::marker::PhantomData<(A, B)>);
impl<A, B> Parser for AndThen<A, B>
where
    A: Stream,
    B: Into<<A::Error as ParseError>::StreamError>,
{
    type PartialState = ();
}
fn expr<A>() -> impl Parser
where
    A: Stream,
{
    AndThen::<A, ()>(core::marker::PhantomData)
}
fn parse_mode_impl<A>()
where
    A::Error: ParseError,
    A: Stream,
{
    Parser::parse_mode(&expr::<A>(), Default::default())
}
EOF

=== stdout ===
=== stderr ===
warning: anonymous parameters are deprecated and will be removed in the next edition
  --> <anon>:16:19
   |
16 |     fn parse_mode(&Self, Self::PartialState) {}
   |                   ^^^^^ help: try naming the parameter or explicitly ignoring it: `_: &Self`
   |
   = note: `#[warn(anonymous_parameters)]` on by default
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
   = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>

warning: anonymous parameters are deprecated and will be removed in the next edition
  --> <anon>:16:26
   |
16 |     fn parse_mode(&Self, Self::PartialState) {}
   |                          ^^^^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: Self::PartialState`
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
   = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>

warning: function is never used: `expr`
  --> <anon>:26:4
   |
26 | fn expr<A>() -> impl Parser
   |    ^^^^
   |
   = note: `#[warn(dead_code)]` on by default

warning: function is never used: `parse_mode_impl`
  --> <anon>:32:4
   |
32 | fn parse_mode_impl<A>()
   |    ^^^^^^^^^^^^^^^

warning: 4 warnings emitted

==============