astgen: improved handling of coercion

GenZir struct now has rl_ty_inst field which tracks the result location
type (if any) a block expects all of its results to be coerced to.

Remove a redundant coercion on const local initialization with a
specified type.

Switch expressions, during elision of store_to_block_ptr instructions,
now re-purpose them to be type coercion when the block has a type in the
result location.
3cebaaad1cAndrew Kelley committed on 4/1/2021, 1:05:37 AMparent08eedc9
4 files changedLine totals unavailable