Some texture and SB operations can take non-integer indexes, which should be
cast to integers before use if they are not already. This adds makeIntegerIndex()
for the purpose. Int types are left alone.
(This was done before for operator[], but needs to apply to some other things
too, hence its extraction into common function now)
This PR adds the ability to pass structuredbuffer types by reference
as function parameters.
It also changes the representation of structuredbuffers from anonymous
blocks with named members, to named blocks with pseudonymous members.
That should not be an externally visible change.
New command line option --shift-ssbo-binding mirrors --shift-ubo-binding, etc.
New reflection query getLocalSize(int dim) queries local size, e.g, CS threads.
