jaql/parser: fix include order to silence warning with bison-2.6
jaql/parser: fix include order to silence warning with bison-2.6

The jc/struct _jc type isn't known to the tab.h file, so make sure we
have its definition before including it.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb