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.
Use the same instances from class declaration instead
Otherwise, primary constructor value parameter types when used
in the class body are considered as different from types
based on the class type parameters
See the test genericConstructors.kt, before this commit
"id" call was reported in inapplicable
Mikhail Glukhikh