Clarify behavior of work_group_broadcast (#577)

* Clarify behavior of work_group_broadcast

Fix an unrelated typo.
Related to #169.

Signed-off-by: Marco Antognini <[email protected]>

* Improve specification and update sub_group_broadcast

Signed-off-by: Marco Antognini <[email protected]>

* Address typos

Signed-off-by: Marco Antognini <[email protected]>
1 file changed