`TemplateVisitor#visitBoundAttribute` currently has to invoke visiting
expressions manually (this is fixed in #31813). Previously, it did not
bind `targetToIdentifier` to the visitor before deferring to the
expression visitor, which breaks the `targetToIdentifier` code. This
fixes that and adds a test to ensure the closure processed correctly.
This change is urgent; without it, many indexing targets in g3 are
broken.
PR Close#31861
859ebdd836