glsl: In ir_set_program_inouts, handle indexing outside array/matrix bounds.

glsl: In ir_set_program_inouts, handle indexing outside array/matrix bounds.

According to GLSL, indexing into an array or matrix with an
out-of-range constant results in a compile error.  However, indexing
with an out-of-range value that isn't constant merely results in
undefined results.

Since optimization passes (e.g. loop unrolling) can convert
non-constant array indices into constant array indices, it's possible
that ir_set_program_inouts will encounter a constant array index that
is out of range; if this happens, just mark the whole array as used.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>