Add failing test that we can't select eq_any of a Nullable expression…

… into a bool.

diesel_compile_tests/tests/fail/eq_any_is_nullable.rs

@@ -0,0 +1,20 @@
+extern crate diesel;
+
+use diesel::*;
+
+table! {
+    users{
+       id -> Integer,
+       name -> Nullable<Text>,
+    }
+}
+
+fn main() {
+    let mut conn = PgConnection::establish("").unwrap();
+    // Should not be allowed because `users::name` is nullable, so the result of `eq_any` is
+    // nullable as well.
+    let _: Vec<bool> = users::table
+        .select(users::name.eq_any(["foo", "bar"]))
+        .load(&mut conn)
+        .unwrap();
+}