For example, enqueueReadImage is currently defined as follows:
optional WebCLEvent? eventWaitList,
optional WebCLEvent? event);
The 'slicePitch' parameter is redundant/confusing when dealing with 2D images, so we should remove it.
3D image support can be reinstated in a backward-compatible manner by overloading 'rowPitch' so that it can be a single CLuint or a CLuint array.
Fixed by removing 'slicePitch' parameters in enqueue*Image().
NOTE: The corresponding slice pitch parameters in enqueue*BufferRect() must remain in place, because they have nothing to do with 3D images.