mesa: glGet: add script to generate hash tables in build time

mesa: glGet: add script to generate hash tables in build time

This will be needed by the next patch, which will switch to using
the parameter descriptor- and hash tables generated by the script.

The hash algorithm remains the same, the output parameter descriptor
table format changes slightly. There the TYPE_API_MASK entries are
removed and an invalid NULL entry is inserted at the beginning. This is
ok, as get.c:find_value() doesn't rely on TYPE_API_MASK any more to
detect an invalid enum.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Oliver McFadden <oliver.mcfadden@linux.intel.com>