Extension methods on NewType not working since 1.0.0RC16

[dipucian]

Hi~ I'm trying to use NewType in a Scala 2.12 project and found that the example on the micro site about Defining Operators On New Types doesn't compile. The last working version is 1.0.0RC15. The compiler error is something like

value next is not a member of SequenceNumber
    sequenceNumber.next

Scala version: 2.12.19

[dipucian]

Seems like this issue has been highlighted in #949 (comment) before, I hope there is a way to fix that since -Xsource is not recommended for production code.