V3D can do indirect inputs so we don't need it. Also, the lowering
produces horrible if-ladder code that is particularly bad for geometry
shaders where inputs are always arrays and shader bodies usually have
a loop indexing into them.

This fixes a couple of geometry shader tests in CTS that would fail to
register allocate otherwise.

There are no changes in shader-db.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>