Fix anyOrNull matcher with value class wrapping primitive type

[jselbo]

Fixes the first problem mentioned in #555
"anyOrNull with nullable primitive value class matcher throws IllegalStateException"

createInstance value class logic assumed the value class can be constructed with a null value, but this doesn't work when the wrapped type is a primitive.

[TimvdLippe]

@m-koops do you mind reviewing this PR? Thanks!

[m-koops]

@m-koops do you mind reviewing this PR? Thanks!

Sure, NP.

[m-koops]

Hi Joshua, many thanks for providing this PR.

The extra tests that you have added, but which you had to disable with @ignore as they fail at this moment, shed an interesting light on how Kotlin hands over value classes to Java code. So, apart from your direct code improvement, #555 and this PR have provided valueable additional input on the weak spots of value class handling in Mockito-Kotlin.

So far, my impression was that value class are always unboxed when handed over to Java code. But the new test cases proof that in case of primitives as inner value, the value classes are handed over to the Mockito Java code as-is, say boxed.

@TimvdLippe, apart from the unused import that I marked with a comment, this PR is ready to be accepted.

As follow-up, I will have a look into the boxing and unboxing behavior of value classes in general and hopefully I can soon provide a fix that will make the new ignored test cases succeed.

Cheers, Mark

[TimvdLippe]

Thanks for the PR and the review!