A dispatch whose group count exceeds maxComputeWorkGroupCount aborted the
process; a software device (lavapipe) reports the spec minimum 65535, and
Ghost of Yotei (PPSA26344) dispatches 129199x1x1 in its presentation path.
The count is now recorded as consecutive vkCmdDispatchBase chunks of at
most the limit per dimension, each continuing the grid at its base offset
(a plain vkCmdDispatch would restart group ids at 0 and re-execute the
first chunk's workgroups), with a barrier between chunks so a later chunk
sees an earlier one's writes. Compute pipelines are created with
VK_PIPELINE_CREATE_DISPATCH_BASE_BIT, which a nonzero base requires.
A split on NVIDIA throws instead of dispatching: measured on an RTX 5070
Ti, the driver drops the first workgroups of a vkCmdDispatchBase dispatch
with a nonzero base (reproduced with a standalone Vulkan program outside
this repository), so its 65535 Y/Z limits cannot be split through. A split
of a dispatch whose LDS lives in device memory also throws: its buffer
slot base is computed from gl_NumWorkGroups, which inside a chunk is the
chunk's count, so workgroups of different chunks would alias (a 1D X split
only works because the base degenerates to the group id).
Fixes#3212
288ee89d2d