When rendering views an anonymous subclass is created by calling
ActionView::Base.with_empty_template_cache.
This causes inspect to return an unhelpful description when calling
inspect:
`#<#<Class:0x012345012345>:<0x012345012345>`.

This can be confusing when exceptions are raised because it's hard to
figure out where to look. For example calling an undefined method in a
template would raise the following exception:

    undefined method `undefined' for #<#<Class:0x012345012345>:<0x012345012345>

Instead we can return the non-anonymous superclass name.

    undefined method `undefined' for #<ActionView::Base:0x01234502345>

The anonymous class is created in ActionView::Base.with_empty_template_cache.
See f9bea630
This seems to be done for performance reasons only, without expecting a
change to calling `inspect`.