Merge #399

399: Improve error diagnostics in generic argument handling r=philberty a=philberty

When we get GenericBindings such as ::<A=...> this is not allowed
in this context. We can also improve the unexpected number of argument
errors to print the number of expected vs received arguments

An example error message looks like:
```
test.rs:4:12: error: generic item takes at least 1 type arguments but 0 were supplied
    1 | struct Foo<A>(A);
      |            ~
......
    4 |     let a: Foo = Foo::<i32>(123);
      |            ^

```

Co-authored-by: Philip Herron <philip.herron@embecosm.com>
Co-authored-by: Marc Poulhiès <dkm@kataplop.net>

0 files changed, 0 insertions, 0 deletions