Performance decrease when called from anonymous function

[v-kuropatka]

I noticed some strange behavior when JSON.Serialize is called via anonymous function. Consider following benchmark:

    [MemoryDiagnoser]
    public class SerializersBenchmark
    {
        private Action<object> jilSerializer = o => JSON.Serialize(o, Options.ISO8601);
        private static readonly SomePerson Person = new SomePerson
        {
            FirstName =  "John",
            LastName = "Doe"
        };

        [Benchmark]
        public void JilSerializer()
        {
            JSON.Serialize(Person, Options.ISO8601);
        }

        [Benchmark]
        public void JilSerializerThroughAction()
        {
            jilSerializer(Person);
        }

        public class SomePerson
        {
            public string FirstName { get; set; }
            public string LastName { get; set; }
        }
    }

Here are results:

Method	Mean	Error	StdDev	Gen 0	Gen 1	Gen 2	Allocated
JilSerializer	260.8 ns	1.61 ns	1.43 ns	0.0525	-	-	440 B
JilSerializerThroughAction	447.5 ns	2.87 ns	2.69 ns	0.0677	-	-	568 B

You can see significant performance reduction and increase of memory allocation. Could you please advise how to avoid it?