Before this commit, extension receivers were declared only for
properties with container source, which is strange & inconsistent.
Now we declare accessor extension receiver iff corresponding property
has extension receiver.
This patch mutes the following test categories:
* Tests with java dependencies (System class,
java stdlib, jvm-oriented annotations etc).
* Coroutines tests.
* Reflection tests.
* Tests with an inheritance from the standard
collections.
Mikhail Glukhikh