To support dynamic types and method dispatch, my programming language introduces a type called dynamic. When calling a method on a callee whose type is dynamic, the compiler first pushes the callee and all arguments on the stack, and then generates an invokedynamic instruction instead of a normal invoke* instruction. The instruction points to a special bootstrap method in a class called DynamicLinker, but only static types are available when it is called.
My Problem: How do I get the runtime type of the arguments that were passed to the invokedynamic instruction?
The "dynamic" part of invokedynamic does not mean that a method arguments can have dynamic types. It rather means that the behavior of invoke instruction can be customized. The exact types of invokedynamic arguments are known at compile time.