Fix suggestion to introduce explicit lifetime

src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.rs

@@ -0,0 +1,26 @@
+// Regression test for #81650
+
+struct Foo<'a> {
+    x: &'a mut &'a i32,
+}
+
+impl<'a> Foo<'a> {
+    fn bar<F, T>(&self, f: F)
+    where
+        F: FnOnce(&Foo<'a>) -> T,
+        F: 'a,
+    {}
+}
+
+trait Test {
+    fn test(&self);
+}
+
+fn func<T: Test>(foo: &Foo, t: T) {
+    foo.bar(move |_| {
+    //~^ ERROR the parameter type `T` may not live long enough
+        t.test();
+    });
+}
+
+fn main() {}

src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.stderr

@@ -0,0 +1,21 @@
+error[E0311]: the parameter type `T` may not live long enough
+  --> $DIR/missing-lifetimes-in-signature-2.rs:20:9
+   |
+LL | fn func<T: Test>(foo: &Foo, t: T) {
+   |         -- help: consider adding an explicit lifetime bound...: `T: 'a +`
+LL |     foo.bar(move |_| {
+   |         ^^^
+   |
+note: the parameter type `T` must be valid for the anonymous lifetime #2 defined on the function body at 19:1...
+  --> $DIR/missing-lifetimes-in-signature-2.rs:19:1
+   |
+LL | fn func<T: Test>(foo: &Foo, t: T) {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: ...so that the type `[closure@$DIR/missing-lifetimes-in-signature-2.rs:20:13: 23:6]` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature-2.rs:20:9
+   |
+LL |     foo.bar(move |_| {
+   |         ^^^
+
+error: aborting due to previous error
+