7703: Allow comments between newlines in chaining hints r=Veykril a=unratito
Currently, chaining hints are not generated if there are comments between newlines, which is a very common pattern:
```rust
let vec = (0..10)
// Multiply by 2
.map(|x| x * 2)
// Add 3
.map(|x| x + 3)
.collect::<Vec<i32>>();
```
Besides, it seems a bit weird that this piece of code generates a chaining hint:
```rust
let vec = (0..10)
.collect::<Vec<i32>>();
```
But this one doesn't:
```rust
let vec = (0..10)
// This is a comment
.collect::<Vec<i32>>();
```
Co-authored-by: Paco Soberón <unratito@gmail.com>