Declare tentative return types for Zend (#7251)

Co-authored-by: Nikita Popov <nikita.ppv@gmail.com>

Fix throwing of yield from related exceptions into generator

Use the general zend_generator_throw_exception() helper for this.
Otherwise we don't handle the off-by-one opline correctly (

Fix throwing of yield from related exceptions into generator

Use the general zend_generator_throw_exception() helper for this.
Otherwise we don't handle the off-by-one opline correctly (should
we maybe just stop doing that?)

This is a followup to ad750c3bb6e7b48384c6265eb9d3bcf5b4000652,
which fixed a different yield from exception handling problem that
happened to show up in the same test case from oss-fuzz #25321.
Now both issues should be fixed.

show more ...

Fix handling of exception if valid() during yield from

Fixes oss-fuzz #25296.