Fix #19369 - duplicate macro execution in unapply methods

[jchyb]

It looks like the macro really was called twice - first an unapply application is typed in typedUnapply (and thus the transparent inline macro expansion is run), and then a custom method inlinedUnapply is run (which inlines the unapply and also also wraps the unapply with a anon class). I've disabled inlining for the first call, so now only the second should be run.

I've had some trouble preparing the tests, as it is impossible in our test suite to inspect stdout in a clean way and warnings/report would only be reported once. I remembered, however, that this issue caused me another problem when inspecting trees of splice owner and macro expansion would get triggered recursively, which is also fixed by this, as the first, now disabled call, was run in a bit of a non-standard context. Hopefully this test is enough.

Fixes #19369

[jchyb]

Just noticed the same fix was already submitted (with a better test), so closing