Ruby: &[SPACE][identifier] syntax breaks Ruby parsing

CodeQL's Ruby breaks parsing breaks for the following code:

```ruby
sorted_array = array.sort(& custom_sorts[params[:sortby]])
```

I understand that the following *should* be how this is written, but sometimes people put weird syntax in and it shouldn't break a whole file being parsed:

```ruby
sorted_array = array.sort(&custom_sorts[params[:sortby]])
```

Start by reproducing the Ruby parser failure with the two sort examples in the issue, focusing on the space between `&` and the identifier. Trace the parser entry point that handles this syntax and verify that both forms are accepted without preventing the rest of the file from being parsed.

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