FIXME(49821) remove fixme since a tip about let binding is given

Author: nivkner

src/test/ui/issues/issue-36082.ast.stderr

@@ -1,5 +1,5 @@
 error[E0597]: borrowed value does not live long enough
-  --> $DIR/issue-36082.rs:23:19
+  --> $DIR/issue-36082.rs:21:19
    |
 LL |     let val: &_ = x.borrow().0;
    |                   ^^^^^^^^^^  - temporary value dropped here while still borrowed

src/test/ui/issues/issue-36082.mir.stderr

@@ -1,5 +1,5 @@
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/issue-36082.rs:23:19
+  --> $DIR/issue-36082.rs:21:19
    |
 LL |     let val: &_ = x.borrow().0;
    |                   ^^^^^^^^^^  - temporary value is freed at the end of this statement

src/test/ui/issues/issue-36082.rs

@@ -11,8 +11,6 @@
 // revisions: ast mir
 //[mir]compile-flags: -Z borrowck=mir
 
-// FIXME(#49821) -- No tip about using a let binding
-
 use std::cell::RefCell;
 
 fn main() {