Improve Active View Overview guide. [ci skip]
Merge pull request #11401 from dpdawson/master

Improved Active View Overview guide. [ci skip]
move `MissingHelperError` out of the `ClassMethods` module.
add test-case to verify `error.path` when a helper was not found.

This verifies the code added with:
https://github.com/rails/rails/commit/99c9d18601539c7e7e87f26bb047add1f93072af
Typo fix [skip ci]
Merge pull request #11414 from ankit8898/typo

Typo fix [skip ci]
Removing Gem.source_index [ci skip]
Merge pull request #11417 from arunagw/gem_source_index_no_required

Removing Gem.source_index [ci skip]
Remove update:application_controller rake task.
Merge pull request #11420 from simi/remove_update_application_controller_task

Remove update:application_controller rake task.
Remove block argument from callback example.

[ci skip]
Merge pull request #11413 from envylabs/master

Remove block argument from callback example. [ci skip]
Removed unused file! Moved to actionview

Removed unused file as this has been
moved to actionview
Merge pull request #11421 from arunagw/actionpack_activerecord_remove

Removed unused file! Moved to actionview