Box primitive casts in Whitebox.getInternalState/invokeMethod reflection

[MBoegers]

What

PowerMockWhiteboxGetInternalStateToJavaReflection and PowerMockWhiteboxInvokeMethodToJavaReflection produced non-compiling output when the migrated result was assigned to a primitive-typed local:

int count = (int) countField.get(service);   // does not compile

Field.get/Method.invoke return Object, and Java forbids a direct (int) Object cast.

Fix

Cast to the wrapper; the assignment auto-unboxes:

int count = (Integer) countField.get(service);

A small boxedCastType helper on the shared WhiteboxToReflectionVisitor maps primitive keywords to their wrappers; reference-typed casts are unchanged.

Tests

Added a primitiveResultUsesBoxedCast case to each recipe's test. Existing reference-typed cases are unaffected.