Proper handling of effectively identically parameter lists

[SirYwell]

When combining multiple method handles, the parameter lists are often allowed to be effectively identical. We currently often just ignore that, expecting identical parameter lists or returning incomplete types (missing trailing parameters).

Instead, we should properly handle such situations with a common infrastructure all relevant methods can benefit from.
For example, it might make sense to introduce a ParameterList type. This could also help in situations where the return type is known but the length of the parameter list isn't known. This would further make analysis more precise, building upon #18.