enums,gallium: lower 64-bit attribs in drivers, change VERT_ATTRIB_EDGEFLAG, st/mesa cleanups
The main motivation is to simplify st/mesa by removing lowering of 64-bit vertex attribs and
index_to_input to make the st/mesa code easier to work with for future work.
VERT_ATTRIB_EDGEFLAGis changed to 31, and with that all relevant code in mesa/vbo/tnl is changed. (prerequisite for the removal of
- gallium gets
PIPE_VFORMAT_*enums for vertex attribs to pack pipe_vertex_element nicely.
- Lowering 64-bit vertex attribs is moved to gallium drivers (calling a helper) to simplify st/mesa.
- Cleanups in dd and st/mesa draw functions.