Backport from 4.0: Fix bug in MySQL-3.23 ORDER BY from a table with no PRIMARY KEY and where the user had added UNIQUE indexes with CREATE INDEX
pars0grm.y:
  Move inclusion of math.h after univ.i also in the .y file; this fix is already done in 4.0


innobase/pars/pars0grm.y:
  Move inclusion of math.h after univ.i also in the .y file; this fix is already done in 4.0
sql/ha_innobase.cc:
  Backport from 4.0: Fix bug in MySQL-3.23 ORDER BY from a table with no PRIMARY KEY and where the user had added UNIQUE indexes with CREATE INDEX