llvm-project

fbbaa545 - [mlir][async] Lazily create the coroutine destroy-cleanup block (#199583)

[mlir][async] Lazily create the coroutine destroy-cleanup block (#199583) `setupCoroMachinery` previously emitted a `cleanupForDestroy` block unconditionally, alongside the normal `cleanup` block. That block is only ever used as the "destroy" successor of an `async.coro.suspend`, so for coroutines that never suspend (e.g. an `async.func` whose body contains no `async.await`) it ended up unreachable in the lowered CFG. Make `cleanupForDestroy` mirror the existing `setError` (and `setupSetErrorBlock`) pattern and materialize it lazily via a new `setupCleanupForDestroyBlock` helper, called only from the two places (`outlineExecuteOp` and the `async.await` lowering) that actually wire it up. Store the coroutine id on `CoroMachinery` so the helper can rebuild the block contents without keeping the original `async.coro.id` op around. This change is in preparation of adding a new builtin token type. Dead `async.coro.free` ops are inefficient and cause problems in the lowering to LLVM. Assisted-by: Opus 4.7