Merge #1661

1661: Parse function parameters attributes r=matklad a=eupn

Fixes #1397. The [RFC-2565](https://github.com/rust-lang/rfcs/blob/master/text/2565-formal-function-parameter-attributes.md) specifies `#[attributes]` to function parameters:

```rust
fn foo(#[attr] a, #[unused] b, #[must_use] ...) {
    // ...
}
```

This PR adds those attributes into grammar and to the parser, extending corresponding inline tests.

Co-authored-by: Evgenii P <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 817dedfbf..f2c20573e 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -642,12 +642,14 @@ Grammar(
         "SelfParam": (
             traits: [
                 "TypeAscriptionOwner",
+                                "AttrsOwner",
             ]
         ),
         "Param": (
             options: [ "Pat" ],
             traits: [
                 "TypeAscriptionOwner",
+                                "AttrsOwner",
             ]
         ),
         "UseItem": (