#29 Math.pow problems

[Wu Gansha]

Our implementation of Math.pow calls libc pow
directly. But I found there're times pow doesn't work
correctly when running JBB2000 with O3.
That is, pow(10.0, -3.0) produces negative infinity. I
don't know what's the cause. This will happen only
once, but always repeatable.
Temporarily I use a patch to compare the result, if
it's abnormal then execute pow again.
When JBB2000 could run, hope other guys could repeat
the problem and give a real patch.