At present, libstdc++ will not build.  My understanding is that it needs to have
the NuttX libc characterized in crossconfig.m4.  This is a first attempt to do that --
unfortunately, it still does not work.

diff -u gcc-4.2.4/libstdc++-v3/configure.orig gcc-4.2.4/libstdc++-v3/configure
--- gcc-4.2.4/libstdc++-v3/configure.orig	2009-01-05 17:52:11.000000000 -0600
+++ gcc-4.2.4/libstdc++-v3/configure	2009-01-05 17:52:43.000000000 -0600
@@ -108515,9 +108515,7 @@
 
     ;;
   *)
-    { { echo "$as_me:$LINENO: error: No support for this host/target combination." >&5
-echo "$as_me: error: No support for this host/target combination." >&2;}
-   { (exit 1); exit 1; }; }
+  # Assume bare hardware
    ;;
 esac
 
diff -u gcc-4.2.4/libstdc++-v3/crossconfig.m4.orig gcc-4.2.4/libstdc++-v3/crossconfig.m4
--- gcc-4.2.4/libstdc++-v3/crossconfig.m4.orig	2009-01-05 17:51:07.000000000 -0600
+++ gcc-4.2.4/libstdc++-v3/crossconfig.m4	2009-01-05 17:52:02.000000000 -0600
@@ -412,7 +412,7 @@
     AC_DEFINE(HAVE_TANHL)
     ;;
   *)
-    AC_MSG_ERROR([No support for this host/target combination.])
+   # Assume bare hardware
    ;;
 esac
 ])