.method public hidebysig static vararg void VarArg() cil managed
{
    .maxstack 8
    .locals init (
        [0] valuetype [mscorlib]System.ArgIterator args,
        [1] valuetype [mscorlib]System.TypedReference tref)
    L_0000: ldloca args
    L_0004: arglist 
    L_0006: call instance void [mscorlib]System.ArgIterator::.ctor(valuetype [mscorlib]System.RuntimeArgumentHandle)
    L_000b: ldloca args
    L_000f: mkrefany [mscorlib]System.ArgIterator
    L_0014: stloc tref
    L_0018: ldloca args
    L_001c: call instance valuetype [mscorlib]System.TypedReference [mscorlib]System.ArgIterator::GetNextArg()
    L_0021: refanyval int64
    L_0026: ldind.i8 
    L_0027: call void [mscorlib]System.Console::WriteLine(int64)
    L_002c: ret 
}

The PEverify states below

[IL]: Error: [xxx.exe : TestClass::VarArg][mdToken=0x6000001][offset 0x0000000F] Mkrefany on TypedReference, ArgHandle, or ArgIterator.(Error: 0x801318B7)