nv50/ir/nir: run assignSlots

nv50/ir/nir: run assignSlots

v2: add support for geometry shaders
    set idx
    add some missing mappings
    fix for 64bit inputs/outputs
    fix up some FP color output index messup
    parse centroid flag
v3: fix arrays in outputs as well
    fix input/ouput size calculation for tessellation shaders
v4: add getSlotAddress helper
    fix for 64 bit typed inputs
v5: change getSlotAddress interface for easier use
    fix sample inputs
    fix slot counting for mat
v7: fix driver_location of images
v8: don't require C++11 features
v9: convert to C++ style comments
    support VERT_ATTRIB_POINT_SIZE
    add more error checking to slots

Signed-off-by: Karol Herbst <kherbst@redhat.com>