compile fails on hypot

[larsbj at lyx dot org (Lars Gullik Bjønnes)]

../../../../libstdc++-v3/src/complex.cc: In function `_Tp std::abs(const
   std::complex<_Tp>&) [with _Tp = double]':
../../../../libstdc++-v3/src/complex.cc:54: `hypot' undeclared (first use this
   function)
../../../../libstdc++-v3/src/complex.cc:54: (Each undeclared identifier is
   reported only once for each function it appears in.)
make[4]: *** [complex.lo] Error 1                               

Linux RH 6.2 ++
glibc-2.1.3-15 

../configure --enable-libstdcxx-v3 --enable-languages=c++ --enable-shared --enable-cshadow-headers 
make bootstrap

from i586-pc-linux-gnu/libstdc++-v3/config.h 
/* Define if you have the hypot function.  */
#define HAVE_HYPOT 1
 
/* Define if you have the hypotf function.  */
#define HAVE_HYPOTF 1
 
/* Define if you have the hypotl function.  */
#define HAVE_HYPOTL 1
       

cd /usr/include ; rgrep -r -x h hypot *
bits/mathcalls.h:__MATHCALL (hypot,, (_Mdouble_ __x, _Mdouble_ __y));
bits/mathinline.h:/* The argument range of the inline version of hypotl is slightly reduced.  */
bits/mathinline.h:__inline_mathcode2 (hypot, __x, __y, return __sqrtl (__x * __x + __y * __y))
g++-3/std/complext.h:// Some targets don't provide a prototype for hypot when -ansi.
g++-3/std/complext.h:extern "C" double hypot (double, double) __attribute__ ((const));
g++-3/std/complext.h:  return hypot (real (x), imag (x));
kpathsea/c-vararg.h:   header, and once in a (hypothetical) VA_START1.  */
python1.5/config.h:/* Define if you have the hypot function.  */
python1.5/mymath.h:extern double hypot Py_PROTO((double, double));
python1.5/mymath.h:#define hypot we_dont_want_faulty_hypot_decl
python1.5/mymath.h:#undef hypot
slang/slang.h:extern double SLmath_hypot (double x, double y);
tgmath.h:#define hypot(Val1, Val2) __TGMATH_BINARY_REAL_ONLY (Val1, Val2, hypot)

nm /lib/libc-2.1.3.so | grep hypot                             
<empty>


        Lgb