Add RateLimit benchmarks (#910)

* Add RateLimit benchmarks

Add benchmarks for the rate-limit policy.

* Change NuGet baseline

The latest release is 7.2.3, not 7.3.0.

src/Polly.Benchmarks/PollyConfig.cs

@@ -28,7 +28,7 @@ private static Job PollyJob(Job job, bool useNuGet)
 
             if (useNuGet)
             {
-                result = result.WithNuGet("Polly", "7.2.1");
+                result = result.WithNuGet("Polly", "7.2.3");
             }
 
             return result;

src/Polly.Benchmarks/RateLimit.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Threading.Tasks;
+using BenchmarkDotNet.Attributes;
+
+namespace Polly.Benchmarks
+{
+    [Config(typeof(PollyConfig))]
+    public class RateLimit
+    {
+        private static readonly Policy SyncPolicy = Policy.RateLimit(20, TimeSpan.FromSeconds(1), int.MaxValue);
+        private static readonly AsyncPolicy AsyncPolicy = Policy.RateLimitAsync(20, TimeSpan.FromSeconds(1), int.MaxValue);
+
+        [Benchmark]
+        public void RateLimit_Synchronous_Succeeds()
+        {
+            SyncPolicy.Execute(() => Workloads.Action());
+        }
+
+        [Benchmark]
+        public async Task RateLimit_Asynchronous_Succeeds()
+        {
+            await AsyncPolicy.ExecuteAsync(() => Workloads.ActionAsync());
+        }
+
+        [Benchmark]
+        public int RateLimit_Synchronous_With_Result_Succeeds()
+        {
+            return SyncPolicy.Execute(() => Workloads.Func<int>());
+        }
+
+        [Benchmark]
+        public async Task<int> RateLimit_Asynchronous_With_Result_Succeeds()
+        {
+            return await AsyncPolicy.ExecuteAsync(() => Workloads.FuncAsync<int>());
+        }
+    }
+}