`UNREACHABLE_CODE` is weird.
If we look into its
positioning strategy,
we'll see that this diagnostic
attempts to split the source
of its element into multiple ranges.
This is bad, because such smaller
ranges can easily overlap with other
diagnostics in such a way that
they are no longer hierarchical.
See the
`compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/3.kt` test
for an example of this behavior
(allow reporting `UNREACHABLE_CODE`
first). The problem will appear at
the condition of `case_7`.
Nikolay Lunyak
110cc79ddd