Gather together usefulness tests

I took most tests that were testing only for match exhaustiveness,
pattern refutability or match arm reachability, and put them in
the same test folder.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/test/ui/pattern/usefulness/refutable-pattern-in-fn-arg.rs b/src/test/ui/pattern/usefulness/refutable-pattern-in-fn-arg.rs
new file mode 100644
index 00000000000..a2d9e1935de
--- /dev/null
+++ b/src/test/ui/pattern/usefulness/refutable-pattern-in-fn-arg.rs
@@ -0,0 +1,5 @@
+fn main() {
+    let f = |3: isize| println!("hello");
+    //~^ ERROR refutable pattern in function argument: `_` not covered
+    f(4);
+}