Move /src/test to /tests

tests/ui/lint/warn-path-statement.rs

@@ -0,0 +1,17 @@
+// compile-flags: -D path-statements
+struct Droppy;
+
+impl Drop for Droppy {
+    fn drop(&mut self) {}
+}
+
+fn main() {
+    let x = 10;
+    x; //~ ERROR path statement with no effect
+
+    let y = Droppy;
+    y; //~ ERROR path statement drops value
+
+    let z = (Droppy,);
+    z; //~ ERROR path statement drops value
+}