Move /src/test to /tests

tests/rustdoc/duplicate_impls/impls.rs

@@ -0,0 +1,12 @@
+pub struct Foo;
+
+// just so that `Foo` doesn't show up on `Bar`s sidebar
+pub mod bar {
+    pub trait Bar {}
+}
+
+impl Foo {
+    pub fn new() -> Foo { Foo }
+}
+
+impl bar::Bar for Foo {}