results)

Before this fix, the function BENCHMARK() would fail to evaluate expressions
like "(select avg(a) from t1)" in debug builds (with an assert),
or would report a time of zero in non debug builds.

The root cause is that evaluation of DECIMAL_RESULT expressions was not
supported in Item_func_benchmark::val_int().

This has been fixed by this change.


mysql-test/r/func_misc.result:
  Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()
mysql-test/t/func_misc.test:
  Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()
sql/item_func.cc:
  Added support for DECIMAL_RESULT in Item_func_benchmark::val_int()