glsl: expose textureQueryLod in GLSL 4.00+ fragment shaders

glsl: expose textureQueryLod in GLSL 4.00+ fragment shaders

See issue from the ARB_texture_query_lod spec for LOD vs Lod confusion:

    (3) The core specification uses the "Lod" spelling, not "LOD".  Should
        this extension be modified to use "Lod"?

      RESOLVED: The "Lod" spelling is the correct spelling for the core
      specification and the preferred spelling for use. However, use of
      "LOD" also exists, as the extension predated the core specification,
      so this extension won't remove use of "LOD".

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Timothy Arceri <t_arceri@yahoo.com.au>