[patch] testsuite fix for math tests on darwin

[Benjamin Kosnik]

>So this patch which removes that check for -lm and also removes it for
>-lmath, these look like they were done before MATH_LIBRARY was around
>so they become redundent.
>
>
>Bootstrapped on powerpc-apple-darwin with no regressions and those test
>cases passes now.

Great. This looks good to me, but I cannot approve this. 

It would be nice if somebody else would, however....

-benjamin