[Nestmates] RFR (S) 8202401: [Nestmates] jshell tests fail due to class redefinition limitation on nested types

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8202401
webrev: http://cr.openjdk.java.net/~dholmes/8202401/webrev/

As jshell tries to use class redefinition when possible, it will hit 
errors if trying to redefine classes in a way that would modify the 
NestHost or NestMembers attributes. It then falls back to an alternative 
technique. For the tests this results in a "signature-change" that is 
unexpected.

The simple fix (courtesy of Jan) is to change the "expects signature 
parameter" from false to true for those test cases.

Thanks,
David