fix most compiler/ doctests

compiler/rustc_middle/src/ty/closure.rs

@@ -293,7 +293,7 @@ pub struct CaptureInfo {
     /// let mut t = (0,1);
     ///
     /// let c = || {
-    ///     println!("{t}"); // L1
+    ///     println!("{t:?}"); // L1
     ///     t.1 = 4; // L2
     /// };
     /// ```
@@ -309,7 +309,7 @@ pub struct CaptureInfo {
     /// let x = 5;
     ///
     /// let c = || {
-    ///     let _ = x
+    ///     let _ = x;
     /// };
     /// ```
     ///
@@ -373,17 +373,19 @@ pub enum BorrowKind {
     /// is borrowing or mutating a mutable referent, e.g.:
     ///
     /// ```
-    /// let x: &mut isize = ...;
+    /// let mut z = 3;
+    /// let x: &mut isize = &mut z;
     /// let y = || *x += 5;
     /// ```
     ///
     /// If we were to try to translate this closure into a more explicit
     /// form, we'd encounter an error with the code as written:
     ///
-    /// ```
-    /// struct Env { x: & &mut isize }
-    /// let x: &mut isize = ...;
-    /// let y = (&mut Env { &x }, fn_ptr);  // Closure is pair of env and fn
+    /// ```compile_fail,E0594
+    /// struct Env<'a> { x: &'a &'a mut isize }
+    /// let mut z = 3;
+    /// let x: &mut isize = &mut z;
+    /// let y = (&mut Env { x: &x }, fn_ptr);  // Closure is pair of env and fn
     /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
     /// ```
     ///
@@ -391,10 +393,11 @@ pub enum BorrowKind {
     /// in an aliasable location. To solve, you'd have to translate with
     /// an `&mut` borrow:
     ///
-    /// ```
-    /// struct Env { x: &mut &mut isize }
-    /// let x: &mut isize = ...;
-    /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
+    /// ```compile_fail,E0596
+    /// struct Env<'a> { x: &'a mut &'a mut isize }
+    /// let mut z = 3;
+    /// let x: &mut isize = &mut z;
+    /// let y = (&mut Env { x: &mut x }, fn_ptr); // changed from &x to &mut x
     /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
     /// ```
     ///