Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/itoa/benches/bench.rs

@@ -0,0 +1,55 @@
+#![feature(test)]
+#![allow(non_snake_case)]
+#![allow(clippy::cast_lossless)]
+
+extern crate test;
+
+macro_rules! benches {
+    ($($name:ident($value:expr))*) => {
+        mod bench_itoa_format {
+            use test::{Bencher, black_box};
+
+            $(
+                #[bench]
+                fn $name(b: &mut Bencher) {
+                    let mut buffer = itoa::Buffer::new();
+
+                    b.iter(|| {
+                        let printed = buffer.format(black_box($value));
+                        black_box(printed);
+                    });
+                }
+            )*
+        }
+
+        mod bench_std_fmt {
+            use std::io::Write;
+            use test::{Bencher, black_box};
+
+            $(
+                #[bench]
+                fn $name(b: &mut Bencher) {
+                    let mut buf = Vec::with_capacity(40);
+
+                    b.iter(|| {
+                        buf.clear();
+                        write!(&mut buf, "{}", black_box($value)).unwrap();
+                        black_box(&buf);
+                    });
+                }
+            )*
+        }
+    }
+}
+
+benches! {
+    bench_u64_0(0u64)
+    bench_u64_half(u32::max_value() as u64)
+    bench_u64_max(u64::max_value())
+
+    bench_i16_0(0i16)
+    bench_i16_min(i16::min_value())
+
+    bench_u128_0(0u128)
+    bench_u128_max(u128::max_value())
+}