Instead of ICEing on incorrect pattern, use delay_span_bug

src/test/ui/fn-in-pat.rs

@@ -0,0 +1,16 @@
+struct A {}
+
+impl A {
+    fn new() {}
+}
+
+fn hof<F>(_: F) where F: FnMut(()) {}
+
+fn ice() {
+    hof(|c| match c {
+        A::new() => (), //~ ERROR expected tuple struct/variant, found method
+        _ => ()
+    })
+}
+
+fn main() {}

src/test/ui/fn-in-pat.stderr

@@ -0,0 +1,9 @@
+error[E0164]: expected tuple struct/variant, found method `<A>::new`
+  --> $DIR/fn-in-pat.rs:11:9
+   |
+LL |         A::new() => (),
+   |         ^^^^^^^^ not a tuple variant or struct
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0164`.