inversed instance should not be reloaded after stale state was changed

check at association reader that record is inverted and should not be reloaded because of stale was changed at target record
add inversed accessor to association class
Add a note to the changelog for #9499
Merge pull request #9499 from dmitry/inverse_instance_should_not_be_reloaded_after_stale_state_change

Inversed instance should not be reloaded after stale state was changed

Conflicts:
	activerecord/CHANGELOG.md