WHERE f1 < n ignored row if f1 was indexed integer column and
f1 = TYPE_MAX ^ n = TYPE_MAX+1. The latter value when treated
as TYPE overflowed (obviously). This was not handled, it is now.


mysql-test/r/range.result:
  show that on an index int column, we no longer disregard
  a field val of TYPE_MAX in SELECT ... WHERE ... < TYPE_MAX+1
mysql-test/t/range.test:
  show that on an index int column, we no longer disregard
  a field val of TYPE_MAX in SELECT ... WHERE ... < TYPE_MAX+1
sql/opt_range.cc:
  Handle overflowing of int-types in range-optimizer.
  Unfortunately requires re-indentation of entire block.
  Overflow (err == 1) was handled, but only if
  field->cmp_type() != value->result_type(), which it
  just wasn't in our case.