Up-to-date check is very heavy for intellij repo due to artifact size.
If module directory in repo is written only by one task we can assume
that task if up-to-date if target directory exists.
In this mode, instead of analyzing files and generating bytecode for
them, compiler just saves imports of each file in JSON map of form
'<path to file> -> [<import1>, <import2>, ...]'
It is needed for some external tools, notably for Google3 toolchain.
Sergey Rostov