add a test of define_method with shareable Proc.
a method defined by define_method with normal Proc can not cross ractors because the normal Proc is not shareable. However, shareable Proc can be crossed between ractors, so the method with shareable Proc should be called correctly.
add a test of define_method with shareable Proc.
a method defined by define_method with normal Proc can not cross
ractors because the normal Proc is not shareable. However,
shareable Proc can be crossed between ractors, so the method with
shareable Proc should be called correctly.