Type parameters checks are inconsistent and incomplete

[flaper87]

The way we currently check type parameters is inconsistent and error prone. The code below compiles and it shouldn't.

The resolve phase currently ignores these checks and leaves them up to typeck, collect and check, which as demonstrated by bugs like this one and #20302 makes this check unsound.

fn is_copy<T: ::std::marker<i32>::Copy>() {}

fn main() {}

[steveklabnik]

Triage: this still compiles.

[Mark-Simulacrum]

Triage: Still compiles.

[Mark-Simulacrum]

Marking as E-needstest.

error[E0109]: type parameters are not allowed on this type
 --> test.rs:1:29
  |
1 | fn is_copy<T: ::std::marker<i32>::Copy>() {}
  |                             ^^^ type parameter not allowed

error: aborting due to previous error(s)