mesa/formatquery: support for MAX_COMBINED_DIMENSIONS

mesa/formatquery: support for MAX_COMBINED_DIMENSIONS

It is implemented combining the values returned by calls to the 32-bit
query _mesa_GetInternalformati32v.

The main reason is simplicity. The other option would be C&P how we
implemented the support of GL_MAX_{WIDTH/HEIGHT/DEPTH} and GL_SAMPLES.

Additionally, doing this way, we avoid adding checks on the code, as
are done by the call to the query itself.

MAX_COMBINED_DIMENSIONS is the only pname pointed on the spec of
needing a 64-bit query. We handle that possibility by packing the
returning value on the two first 32-bit integers of params. This
would work on the 32-bit query as far as the value is not greater
that INT_MAX. On the 64-bit query wrapper we unpack those values
in order to get the final value.

Reviewed-by: Dave Airlie <airlied@redhat.com>