glsl: add temporary copy_shader_info() function

glsl: add temporary copy_shader_info() function

This function is added here to ease refactoring towards using the new shared
shader_info. Once refactoring is complete and values are set directly it
will be removed.

We call it from _mesa_copy_linked_program_data() rather than glsl_to_nir()
so that the values will be set for all drivers. In order to do this some
calls need to be moved around so that we make sure to call
do_set_program_inouts() before _mesa_copy_linked_program_data()

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>