Separating atomic opcodes makes possible to express a6xx global
atomics which take iova in SRC1. They would be needed by
VK_KHR_buffer_device_address.
The change also makes easier to distiguish atomics in conditions.
Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8717>