acinclude.m4 (GLIBCPP_CHECK_COMPLEX_MATH_SUPPORT): Check for cabs, cabsf, and cabsl, too.

        * acinclude.m4 (GLIBCPP_CHECK_COMPLEX_MATH_SUPPORT): Check
        for cabs, cabsf, and cabsl, too.
        * aclocal.m4: Regenerated.
        * config.h.in: Likewise.
        * configure: Likewise.
        * libmath/Makefile.am (libmath_la_SOURCES): Remove cabs.c and
        cabsf.c.
        * libmath/Makefile.in: Regenerated.
        * libmath/complex-stub.h (cabs): Don't declare if the system
        already provides this function.
        (cabsf): Likewise.
        (cabsl): Likewise.
        * src/complex.cc (abs): Directly use `hypot' since we can't call
        cabs on IRIX.

From-SVN: r37145