Fix ICE with explicit late-bound lifetimes

src/test/ui/issues/issue-72278.rs

@@ -0,0 +1,19 @@
+// run-pass
+
+#![allow(unused)]
+
+struct S;
+
+impl S {
+    fn func<'a, U>(&'a self) -> U {
+        todo!()
+    }
+}
+
+fn dont_crash<'a, U>() -> U {
+    S.func::<'a, U>()
+    //~^ WARN cannot specify lifetime arguments explicitly
+    //~| WARN this was previously accepted
+}
+
+fn main() {}

src/test/ui/issues/issue-72278.stderr

@@ -0,0 +1,15 @@
+warning: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present
+  --> $DIR/issue-72278.rs:14:14
+   |
+LL |     fn func<'a, U>(&'a self) -> U {
+   |             -- the late bound lifetime parameter is introduced here
+...
+LL |     S.func::<'a, U>()
+   |              ^^
+   |
+   = note: `#[warn(late_bound_lifetime_arguments)]` on by default
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #42868 <https://github.com/rust-lang/rust/issues/42868>
+
+warning: 1 warning emitted
+