glsl: Return -1 for program interface query locations in many cases.

glsl: Return -1 for program interface query locations in many cases.

We were recording locations for all variables, even ones without an
explicit location set.  Implement the rules from the spec, and record
-1 in the resource list accordngly.  Make program_resource_location
stop doing math on negative values.  Remove hacks that are no longer
necessary now that we've stopped doing that.

Fixes 4 dEQP-GLES31.functional.program_interface_query tests:
- program_input.location.separable_fragment.var
- program_input.location.separable_fragment.var_array
- program_output.location.separable_vertex.var_array
- program_output.location.separable_vertex.var_array

v2: Delete more code

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>