Previously only await inside the async function (coroutine after lowering to async runtime) would check the error state
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D109229
Depends On D104999
Automatic reference counting based on the liveness analysis can add a lot of reference counting overhead at runtime. If the IR is known to be constrained to few particular "shapes", it's much more efficient to provide a custom reference counting policy that will specify where it is required to update the async value reference count.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D105037
