Fixed backpatching of forward jumps.
Implemented LOOP, WHILE, REPEAT (temporarily known as SPREPEAT).
Known bug: Expression evaluation still not quite ok (e.g. "x > 0"),
which is why IF and CASE is not yet implemented.
sql/Makefile.am:
Added new sp.h/sp.cc file.
sql/item.h:
New deferred result_type() method in Item_splocal.
sql/lex.h:
Temporary fix until REPEAT conflict is solved. Use SPREPEAT for now.
sql/sp_head.cc:
Moved create/find/drop functions to sp.cc.
Fixed the backpatch stuff.
(Also removed some dead code and updated comments.)
sql/sp_head.h:
Moved create/find/drop declarations to sp.h.
Fixed the backpatch stuff.
sql/sp_pcontext.h:
New method: last_label().
sql/sql_parse.cc:
Include sp.h.
sql/sql_yacc.yy:
Fixed backpatching of forward jumps.
Implemented LOOP, WHILE, and REPEAT. (Note: SPREPEAT for now.)
