- `.ll.kt` test data can be added in cases where LL FIR resolution
legally diverges from K2 compiler results.
- Each `.ll.kt` test is prefixed with an `LL_FIR_DIVERGENCE` directive
which must explain why the test may diverge from K2 compiler results.
- `LLFirDivergenceCommentChecker` ensures that each `.ll.kt` file
contains an `LL_FIR_DIVERGENCE` directive.
- `LLFirIdenticalChecker` results in an assertion error if the `.ll.kt`
test and its base test are completely identical, including in their
meta info (but ignoring `LL_FIR_DIVERGENCE`).
- The checker additionally ensures that the base source file and the
`.ll.kt` source file have identical Kotlin source code (ignoring
meta info and `LL_FIR_DIVERGENCE`). This ensures that both tests
test the exact same thing.
- `.ll.kt` files are ignored by select test generators, in addition to
`.fir.kt` files.
Before this commit, we had effective visibility as a part of FIR status,
so it was integrated into the full pipeline. In this commit,
we introduced "effective visibility as a service" which is now used
only by exposed visibility checker. This allows us to make the thing
universal for all FIR nodes, including nodes for Java / deserialized.
Dmitrii Gridin