i965/fs: Define logical typed and untyped surface opcodes.

i965/fs: Define logical typed and untyped surface opcodes.

Each logical variant is largely equivalent to the original opcode but
instead of taking a single payload source it expects its arguments
separately as individual sources, like:

 typed_surface_write_logical null, coordinates, source, surface,
                                    num_coordinates, num_components

This patch defines the opcodes and usual instruction boilerplate,
including a placeholder lowering function provided mainly as
documentation for their source registers.

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>