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
E.g. in `x + f()` where `f` is an inline lambda, the instructions for
`+` should have the line number of that expression (while previously
they instead had the line number of the last line of the lambda).
^KT-51738 Fixed
Artem Kobzar