The patch adopts and reuses the optimizations from the legacy backend.
The optimizations remove useless temporary variables,
statements and simplify generated JS code.
The optimizations can be disabled by `-Xoptimize-generated-js=false`.
Related to KT-51139
We already have stepping tests for Kotlin/JVM.
They are helpful for testing the correctness of the generated
debugging information.
They are better than line number tests in that they allow to test the
_behavior_, not the generated data. The structure of the data may change
even if the behavior stays the same. For that reason, stepping tests
are more stable.
We are going to deprecate `WITH_RUNTIME` directive. The main reason
behind this change is that `WITH_STDLIB` directive better describes
its meaning, specifically it will add kotlin stdlib to test's classpath.
This solves no immediate deficiency, but is a to-do that arose as part
of an ongoing effort to port the old, slightly too restrictive
checkLocalVariableTable tests to the more "functional" debugger
infrastructure.
This just shaves a little bit of overhead off the test expectations
and couples them less tightly to the specifics of the test
infrastructure.
Artem Kobzar