ICE with phantom types using default type parameters

[omasanori]

Code:

#[feature(default_type_params)];

struct Foo<T> { dummy: T }

struct Bar<T, U = Foo<T>> { dummy: T }

fn main() {
    let _a: Bar<int> = Bar { dummy: 1 };
}

Output:

error: internal compiler error: unexpected failure
This message reflects a bug in the Rust compiler. 
We would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: the compiler hit an unexpected failure path. this is a bug
task 'rustc' failed at 'assertion failed: !ty::type_has_params(t)', /var/tmp/portage/dev-lang/rust-9999/work/rust-9999/src/librustc/middle/trans/common.rs:826

[alexcrichton]

cc @eddyb

[eddyb]

Sadly, the issue is not with phantom types, but it seems I forgot to substitute type params in defaults for other type params:

#[feature(default_type_params)];
struct Foo<T>(T);
struct Bar<T, U = Foo<T>>(T, U); 
fn main() {
    let _: Bar<bool> = Bar(true, Foo(false));
}
// error: mismatched types: expected `Bar<bool>` but found `Bar<bool,Foo<bool>>` (expected type parameter but found bool)