Currently, only gpu.launch_func supports stream-based asynchronicity. This
patch adds the same mode to gpu.launch, and makes kernel outlining preserve
that when converting to gpu.launch_func.
This patch also documents the stream-based model in the operations description,
which was previously missing.
This patch changes the builders for the two launch operations:
To retain the current behavior for gpu.launch one needs to add a `nullptr` for
the new `Value asyncObject` argument after the `ValueRange asyncDependencies`,
and make sure to pass a valid type for the `Type asyncTokenType` parameter if
dependency-based async behavior is intended.
For gpu.launch_func, both stream-based and dependency-based async models now go
through the same builders, which take all three `Type asyncTokenType,
ValueRange asyncDependencies, Value asyncObject` arguments. To retain
stream-based behavior, pass `nullptr, {}` to the first two parameters, while to
retain dependency-based behavior, pass `nullptr` to the third parameter.
Assisted-by: Claude Code
056dae16f7