glsl: Mark as active all elements of shared/std140 block arrays

glsl: Mark as active all elements of shared/std140 block arrays

Commit 1ca25ab (glsl: Do not eliminate 'shared' or 'std140' blocks
or block members) considered as active 'shared' and 'std140' uniform
blocks and uniform block arrays, but did not include the block array
elements. Because of that, it was possible to have an active uniform
block array without any elements marked as used, making the assertion
   ((b->num_array_elements > 0) == b->type->is_array())
in link_uniform_blocks() fail.

Fixes the following 5 dEQP tests:

 * dEQP-GLES3.functional.ubo.random.nested_structs_instance_arrays.18
 * dEQP-GLES3.functional.ubo.random.nested_structs_instance_arrays.24
 * dEQP-GLES3.functional.ubo.random.nested_structs_arrays_instance_arrays.19
 * dEQP-GLES3.functional.ubo.random.all_per_block_buffers.49
 * dEQP-GLES3.functional.ubo.random.all_shared_buffer.36

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83508
Tested-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Timothy Arceri <t_arceri@yahoo.com.au>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>