Andrew Kelley cb785b9c6b Sema: implement coerce_result_ptr for optionals
New AIR instruction: `optional_payload_ptr_set`
It's like `optional_payload_ptr` except it sets the non-null bit.

When storing to the payload via a result location that is an optional,
`optional_payload_ptr_set` is now emitted. There is a new algorithm in
`zirCoerceResultPtr` which stores a dummy value through the result
pointer into a temporary block, and then pops off the AIR instructions
from the temporary block in order to determine how to transform the
result location pointer in case any in-between coercions need to happen.

Fixes a couple of behavior tests regarding optionals.
2021-11-09 23:01:35 -07:00
..
2021-10-15 13:56:27 -04:00
2020-10-31 12:21:49 +02:00