move lint tests into subdirectories

tests/rustdoc-ui/lints/unused.rs

@@ -0,0 +1,14 @@
+// check-pass
+
+// This test purpose is to check that unused_imports lint isn't fired
+// by rustdoc. Why would it? Because when rustdoc is running, it uses
+// "everybody-loops" which replaces parts of code with "loop {}" to get
+// huge performance improvements.
+
+#![deny(unused_imports)]
+
+use std::fs::File;
+
+pub fn f() {
+    let _: File;
+}