bug in new temp allocation

[robertwb]

In the function below, a temp is not marked as unused and gets dereferenced twice.

    def coeffs_bitsize(self):
        """
        Computes the approximate log2 of the maximum of the absolute
        values of the coefficients.

        EXAMPLES:
            sage: from sage.rings.polynomial.real_roots import *
            sage: bernstein_polynomial_factory_ratlist([1, 2, 3, -60000]).coeffs_bitsize()
            15
            sage: bernstein_polynomial_factory_ratlist([65535/65536]).coeffs_bitsize()
            -1
            sage: bernstein_polynomial_factory_ratlist([65536/65535]).coeffs_bitsize()
            1
        """

        # This returns an estimate of the log base 2 of the rational in the
        # list with largest absolute value.  The estimate is an integer,
        # and within +/- 1 of the correct answer.
        r = max([bitsize(c.numerator()) - bitsize(c.denominator()) for c in self.coeffs])
        return r

[robertwb]

Fixed  http://hg.cython.org/cython-devel/rev/82084a7b654e