Increase tolerance on ACos tests when using ICC.
When the intel compiler has vectorization enabled ( -O2/-O3 ) it converts the
adjacent/hypotenuse
divide operation into reciprocal (rcpps) and
multiply (mulps) operations. This causes a change in the expected result that
is larger than the default tolerance of test_equal. So to resolve the problem
we increase the tolerance for acos when using icc.