Add unwrap block assist #4156

Signed-off-by: Benjamin Coenen <5719034+bnjjj@users.noreply.github.com>

Author: bnjjj

crates/ra_assists/src/doc_tests/generated.rs

@@ -740,7 +740,7 @@ fn foo() {
 "#####,
         r#####"
 fn foo() {
-    <|>println!("foo");
+    println!("foo");
 }
 "#####,
     )

crates/ra_assists/src/handlers/unwrap_block.rs

@@ -6,7 +6,7 @@ use ra_syntax::{ast, AstNode};
 
 // Assist: unwrap_block
 //
-// Removes the `mut` keyword.
+// This assist removes if...else, for, while and loop control statements to just keep the body.
 //
 // ```
 // fn foo() {
@@ -18,7 +18,7 @@ use ra_syntax::{ast, AstNode};
 // ->
 // ```
 // fn foo() {
-//     <|>println!("foo");
+//     println!("foo");
 // }
 // ```
 pub(crate) fn unwrap_block(ctx: AssistCtx) -> Option<Assist> {

docs/user/assists.md

@@ -698,7 +698,7 @@ use std::{collections::HashMap};
 
 ## `unwrap_block`
 
-Removes the `mut` keyword.
+This assist removes if...else, for, while and loop control statements to just keep the body.
 
 ```rust
 // BEFORE
@@ -710,6 +710,6 @@ fn foo() {
 
 // AFTER
 fn foo() {
-    ┃println!("foo");
+    println!("foo");
 }
 ```