glsl: Account for interface block lowering in program_resource_visitor.

glsl: Account for interface block lowering in program_resource_visitor.

When program_resource_visitor visits variables that were created by
lower_named_interface_blocks, it needs to do extra work to un-do the
effects of lower_named_interface_blocks and construct the proper API
names.

Fixes piglit test
spec/glsl-1.50/execution/interface-blocks-api-access-members.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>