cygwin bootstrap failure in libstdc++-v3

["Billinghurst, David (CRTS)" <David dot Billinghurst at riotinto dot com>]

3.1 CVS bootstrap fails on cygwin.  Similar bootstrap yesterday was OK.  The
error occurs when compiling libstdc++-v3/src/locale-inst.cc, and seems to be
due to the absence of strtold.  Details below.


/usr/local/obj/gcc/gcc/xgcc -B/usr/local/obj/gcc/gcc/ -nostdinc++
-L/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/src
-L/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/src/.libs
-B/usr/local/i686-pc-cygwin/bin/ -B/usr/local/i686-pc-cygwin/lib/ -isystem
/usr/local/i686-pc-cygwin/include -nostdinc++
-I/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/include/i686-pc-cygwin
-I/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/include
-I/usr/local/src/gcc/libstdc++-v3/libsupc++
-I/usr/local/src/gcc/libstdc++-v3/libmath -g -O2 -fno-implicit-templates
-Wall -Wno-format -W -Wwrite-strings -Winline
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections -g -c
/usr/local/src/gcc/libstdc++-v3/src/locale-inst.cc -o locale-inst.o
/usr/local/src/gcc/libstdc++-v3/src/locale-inst.cc:0: warning:
-ffunction-sections
   may affect debugging on some targets.
/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/include/bits/locale_facets.tc
c: In
   member function `_InIter std::money_get<_CharT, _InIter>::do_get(_InIter,

   _InIter, bool, std::ios_base&, std::_Ios_Iostate&, long double&) const
[with 
   _CharT = char, _InIter = std::istreambuf_iterator<char, 
   std::char_traits<char> >]':
/usr/local/src/gcc/libstdc++-v3/src/locale-inst.cc:57:   instantiated from
here
/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/include/bits/locale_facets.tc
c:249: `strtold'
   undeclared (first use this function)
/usr/local/obj/gcc/i686-pc-cygwin/libstdc++-v3/include/bits/locale_facets.tc
c:249: (Each
   undeclared identifier is reported only once for each function it appears 
   in.)