glapi: Remove support for "short string" mode

glapi: Remove support for "short string" mode

C89 has a fairly short minimum-maximum string length.  To support
compilers limited by the C89 limits, this script had a mode where it
would generate a character array instead of a giant string.  These were
functionally the same, but the code generated for the character array is
HUGE and difficult to read.

As far as I can tell, nothing in Mesa uses '-m short' any more.  The
generated files used to be tracked in revision control, but I think we
stopped using '-m short' when we stopped tracking the generated files.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Tested-by: Brian Paul <brianp@vmware.com>
Tested-by: Lu Hua <huax.lu@intel.com>
Cc: Vinson Lee <vlee@freedesktop.org>