[cxx-interop] Add support for operator! overloading

[bulbazord]

This patch enables operator overloading for operator! when cxx interop is enabled. This is my first patch related to cxx interop, let me know if I should be doing something differently.

@plotfi @zoecarver @hyp

[plotfi]

Nice work Alex. :-)

[bulbazord]

@swift-ci please test

[zoecarver]

Seems good. Thanks.

[zoecarver]

Actually, can you please also update the tests in test/Interop/Cxx/operators/member-inline-typechecker.swift and test/Interop/Cxx/operators/member-inline-module-interface.swift?

[bulbazord]

Okay, I updated the PR. Here's the changelog:

• Removed unneeded operator overload from LoadableBoolWrapper
• Modified the signature of LoadableBoolWrapper::operator! to return a LoadableBoolWrapper. This makes it more consistent with the other tests.
• Added tests to member-inline-typechecker.swift and member-inline-module-interface.swift as requested. I also updated member-inline-silgen.test to keep it consistent.

Let me know if there's anything else you'd like to see changed.

[zoecarver]

This looks great. Thanks again!

[zoecarver]

I'll start the bots once you fix the Windows mangling. If you want me to run the bots so you can see the failure (it will print out the correct mangling) let me know and I can do that.

[bulbazord]

Yes, if you could please trigger the bots to show me the Windows mangling that would be great! I don't have access to a windows machine currently.

[bulbazord]

@swift-ci please test

[bulbazord]

@zoecarver Could you trigger the test bots so I can get an idea of what the windows manglings will be?

[drodriguez]

@swift-ci please smoke test

[bulbazord]

Ok, got the test fixed up for windows. @drodriguez Can you trigger the tests again for me please? Thanks!

[drodriguez]

@swift-ci please smoke test

[bulbazord]

@zoecarver Think this is good to go in now? Or should we wait for the Linux Platform to be unborked?

[drodriguez]

@swift-ci please test Linux platform