Handle parsing match arms with no comma

When parsing a match expression such as:

```
    match (f, g) {
        (Foo::A, 1) => {}
        (Foo::B, 2) => {}
        _ => {}
    }
```

The first match arm here has an empty block expression of {}. This was
being parsed into a CallExpr of {}(Foo::B, 2) which is wrong. The parsing
of match arms are expression statements so they can be a block but must not
consume the semi-colon as it is valid to have a comma to delimit the match
arm or it can be ignored if this is a ExprWithBlock.

Addresses #1081

0 files changed, 0 insertions, 0 deletions