Import 'ryu' crate version 1.0.5

Bug: 163175424
Test: N/A
Change-Id: I7bda5411adccb26198c53ed1cb41fc6bb08468d7
diff --git a/tests/macros/mod.rs b/tests/macros/mod.rs
new file mode 100644
index 0000000..de6fb46
--- /dev/null
+++ b/tests/macros/mod.rs
@@ -0,0 +1,8 @@
+macro_rules! check {
+    ($f:tt) => {
+        assert_eq!(pretty($f), stringify!($f));
+    };
+    (-$f:tt) => {
+        assert_eq!(pretty(-$f), concat!("-", stringify!($f)));
+    };
+}