glsl: Return correct number of coordinate components for cubemap array images.

Cubemap array images are unlike cubemap array samplers in that they don't need
an additional coordinate to index individual cubemaps in the array, instead
they behave like a 2D array of 6n layers, with n the number of cubemaps in the
array.  Take this exception into account.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glsl/glsl_types.cpp

@@ -1225,8 +1225,13 @@ glsl_type::coordinate_components() const
       break;
    }
 
-   /* Array textures need an additional component for the array index. */
-   if (sampler_array)
+   /* Array textures need an additional component for the array index, except
+    * for cubemap array images that behave like a 2D array of interleaved
+    * cubemap faces.
+    */
+   if (sampler_array &&
+       !(base_type == GLSL_TYPE_IMAGE &&
+         sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE))
       size += 1;
 
    return size;