Move /src/test to /tests

tests/ui/proc-macro/trailing-plus.rs

@@ -0,0 +1,14 @@
+// check-pass
+// aux-build:test-macros.rs
+// compile-flags: -Z span-debug
+
+#![no_std] // Don't load unnecessary hygiene information from std
+extern crate std;
+
+extern crate test_macros;
+
+#[test_macros::print_attr]
+fn foo<T>() where T: Copy + {
+}
+
+fn main() {}