Move /src/test to /tests

tests/ui/lint/lint-non-camel-case-with-trailing-underscores.rs

@@ -0,0 +1,11 @@
+// check-pass
+
+#![allow(dead_code)]
+// This is ok because we often use the trailing underscore to mean 'prime'
+
+// pretty-expanded FIXME #23616
+
+#[forbid(non_camel_case_types)]
+type Foo_ = isize;
+
+pub fn main() { }