Merge #7956

7956: Add assist to convert for_each into for loops r=Veykril a=SaiintBrisson

This PR resolves #7821.
Adds an assist to that converts an `Iterator::for_each` into a for loop: 

```rust
fn main() {
    let vec = vec![(1, 2), (2, 3), (3, 4)];
    x.iter().for_each(|(x, y)| {
        println!("x: {}, y: {}", x, y);
    })
}
```
becomes
```rust
fn main() {
    let vec = vec![(1, 2), (2, 3), (3, 4)];
    for (x, y) in x.iter() {
        println!("x: {}, y: {}", x, y);
    });
}
```

Co-authored-by: Luiz Carlos Mourão Paes de Carvalho <luizcarlosmpc@gmail.com>
Co-authored-by: Luiz Carlos <luizcarlosmpc@gmail.com>
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/syntax/src/ast/make.rs

@@ -222,6 +222,9 @@ pub fn expr_if(
     };
     expr_from_text(&format!("if {} {} {}", condition, then_branch, else_branch))
 }
+pub fn expr_for_loop(pat: ast::Pat, expr: ast::Expr, block: ast::BlockExpr) -> ast::Expr {
+    expr_from_text(&format!("for {} in {} {}", pat, expr, block))
+}
 pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
     let token = token(op);
     expr_from_text(&format!("{}{}", token, expr))