Set up compiletest to test the compiler diagnostics in error cases

[dtolnay]

https://github.com/dtolnay/tt-call/tree/4e6d2504cfef3a78b4ab22b8df76a0f519b8f1cb/ui has a setup I like that should be easy to follow. I have some short source files:

#[macro_use]
extern crate tt_call;

tt_call! {
    macro = [{ parse_type }]
    input = [{ [T; ] }]
}

fn main() {}

and the expected compiler stderr for each one:

error: no rules expected the token `]`
 --> $DIR/type-array-no-len.rs:6:20
  |
6 |     input = [{ [T; ] }]
  |                    ^ no rules expected the token `]`

error: aborting due to previous error