This implements improvements/fixes to get all the union, tuple, and array behavior tests passing.
Previously, we lowered parent pointers for field_ptr and element_ptr incompletely. This has now
been improved to recursively lower such pointer.

Also a fix was done to `generateSymbol` when checking a container's layout.
Previously it was assumed to always be a struct. However, the type can also be a tuple, and therefore
panicking. Updating to ask a type's container layout instead allows us to keep a singular branch for both cases.