Boxing List<T> vs Arrays. Thankfully Arrays do the right thing

TestBoxing.cs

using System;
using System.Collections.Generic;
using UnityEditor;

public static class TestBoxing
{
	//
	// Constructors
	//
	static TestBoxing()
	{
		TestBoxing.intArray = new int[42];
		TestBoxing.intList = new List<int>();
		for (int i = 0; i < 42; i++) {
			TestBoxing.intArray[i] = i;
			TestBoxing.intList.Add(i);
		}
	}

	//
	// Static Methods
	//
	[MenuItem("Tools/Test Boxing Arrays")]
	public static void TestArrayIteration()
	{
		int num = 0;
		int[] array = TestBoxing.intArray;
		for (int i = 0; i < array.Length; i++) {
			int num2 = array[i];
			num += num2;
		}
	}

	[MenuItem("Tools/Test Boxing Lists")]
	public static void TestListIteration()
	{
		int num = 0;
		foreach (int current in TestBoxing.intList) {
			num += current;
		}
	}
}

TestBoxingIL.cs

.class public auto ansi abstract sealed TestBoxing
	extends [mscorlib]System.Object
{
	// Fields
	.field private static int32[] intArray
	.field private static class [mscorlib]System.Collections.Generic.List`1<int32> intList

	// Methods
	.method private specialname rtspecialname static 
		void .cctor () cil managed 
	{
		// Method begins at RVA 0xe4278
		// Code size 61 (0x3d)
		.maxstack 5
		.locals init (
			[0] int32
		)

		IL_0000: ldc.i4.s 42
		IL_0002: newarr [mscorlib]System.Int32
		IL_0007: stsfld int32[] TestBoxing::intArray
		IL_000c: newobj instance void class [mscorlib]System.Collections.Generic.List`1<int32>::.ctor()
		IL_0011: stsfld class [mscorlib]System.Collections.Generic.List`1<int32> TestBoxing::intList
		IL_0016: ldc.i4.0
		IL_0017: stloc.0
		IL_0018: br IL_0034
		// loop start (head: IL_0034)
			IL_001d: ldsfld int32[] TestBoxing::intArray
			IL_0022: ldloc.0
			IL_0023: ldloc.0
			IL_0024: stelem.i4
			IL_0025: ldsfld class [mscorlib]System.Collections.Generic.List`1<int32> TestBoxing::intList
			IL_002a: ldloc.0
			IL_002b: callvirt instance void class [mscorlib]System.Collections.Generic.List`1<int32>::Add(!0)
			IL_0030: ldloc.0
			IL_0031: ldc.i4.1
			IL_0032: add
			IL_0033: stloc.0

			IL_0034: ldloc.0
			IL_0035: ldc.i4.s 42
			IL_0037: blt IL_001d
		// end loop

		IL_003c: ret
	} // end of method TestBoxing::.cctor

	.method public hidebysig static 
		void TestArrayIteration () cil managed 
	{
		.custom instance void [UnityEditor]UnityEditor.MenuItem::.ctor(string) = (
			01 00 18 54 6f 6f 6c 73 2f 54 65 73 74 20 42 6f
			78 69 6e 67 20 41 72 72 61 79 73 00 00
		)
		// Method begins at RVA 0xe42c4
		// Code size 37 (0x25)
		.maxstack 2
		.locals init (
			[0] int32,
			[1] int32,
			[2] int32[],
			[3] int32
		)

		IL_0000: ldc.i4.0
		IL_0001: stloc.0
		IL_0002: ldsfld int32[] TestBoxing::intArray
		IL_0007: stloc.2
		IL_0008: ldc.i4.0
		IL_0009: stloc.3
		IL_000a: br IL_001b
		// loop start (head: IL_001b)
			IL_000f: ldloc.2
			IL_0010: ldloc.3
			IL_0011: ldelem.i4
			IL_0012: stloc.1
			IL_0013: ldloc.0
			IL_0014: ldloc.1
			IL_0015: add
			IL_0016: stloc.0
			IL_0017: ldloc.3
			IL_0018: ldc.i4.1
			IL_0019: add
			IL_001a: stloc.3

			IL_001b: ldloc.3
			IL_001c: ldloc.2
			IL_001d: ldlen
			IL_001e: conv.i4
			IL_001f: blt IL_000f
		// end loop

		IL_0024: ret
	} // end of method TestBoxing::TestArrayIteration

	.method public hidebysig static 
		void TestListIteration () cil managed 
	{
		.custom instance void [UnityEditor]UnityEditor.MenuItem::.ctor(string) = (
			01 00 17 54 6f 6f 6c 73 2f 54 65 73 74 20 42 6f
			78 69 6e 67 20 4c 69 73 74 73 00 00
		)
		// Method begins at RVA 0xe42f8
		// Code size 60 (0x3c)
		.maxstack 2
		.locals init (
			[0] int32,
			[1] int32,
			[2] valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<int32>
		)

		IL_0000: ldc.i4.0
		IL_0001: stloc.0
		IL_0002: ldsfld class [mscorlib]System.Collections.Generic.List`1<int32> TestBoxing::intList
		IL_0007: callvirt instance valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<!0> class [mscorlib]System.Collections.Generic.List`1<int32>::GetEnumerator()
		IL_000c: stloc.2
		.try
		{
			IL_000d: br IL_001e
			// loop start (head: IL_001e)
				IL_0012: ldloca.s 2
				IL_0014: call instance !0 valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<int32>::get_Current()
				IL_0019: stloc.1
				IL_001a: ldloc.0
				IL_001b: ldloc.1
				IL_001c: add
				IL_001d: stloc.0

				IL_001e: ldloca.s 2
				IL_0020: call instance bool valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<int32>::MoveNext()
				IL_0025: brtrue IL_0012
			// end loop

			IL_002a: leave IL_003b
		} // end .try
		finally
		{
			IL_002f: ldloc.2
			IL_0030: box valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<int32>
			IL_0035: callvirt instance void [mscorlib]System.IDisposable::Dispose()
			IL_003a: endfinally
		} // end handler

		IL_003b: ret
	} // end of method TestBoxing::TestListIteration

} // end of class TestBoxing