glsl: Prepare standalone compiler to be able to use parameter lists

glsl: Prepare standalone compiler to be able to use parameter lists

As part of the shader-cache work an upcoming change will add new
references to _mesa_add_parameter and _mesa_new_parameter_list from
the glsl code. To prepare for that, and to allow the standalone
glsl_compiler to still link, here we add mesa/program/prog_parameter.c
to the libglsl_util sources.

Then, in order to get *that* to work, we also add to stubs to
standalone_scaffolding:

	_mesa_program_state_flags
	_mesa_program_state_string

These functions aren't actually used by the two functions in
prog_parameter.c that we are actually calling. They are used in other
functions in the same file. So we don't care what the implementation
of these stubs is, (they won't be called by glsl_compiler). We just
need the stubs present so that it can link.

Signed-off-by: Timothy Arceri <timothy.arceri@collabora.com>
Reviewed-by: Eric Anholt <eric@anholt.net>