Bug 234183

+++ This bug was initially created as a clone of Bug #191162 +++

Here's the simplest of all "hello world" programs :

   % cat foo.C
   #include <iostream>

   int main()
   {
     std::cout << "Hello world" << std::endl;
   }

When compiled and linked with default gcc4 options on RHEL4 I get:

   % x86_64-rhel4-4.0.2-g++ foo.C -o foo
   % ldd -u -r foo
   Unused direct dependencies:
           /lib64/tls/libm.so.6
           /lib64/libgcc_s.so.1

[Using "g++ -o foo foo.cc -v" shows that] libm is indeed being pulled in
(newlines added for legibility):

   /usr/libexec/gcc/x86_64-redhat-linux/4.0.2/collect2
   --eh-frame-hdr
   -m elf_x86_64
   -dynamic-linker /lib64/ld-linux-x86-64.so.2
   -o foo
   /usr/lib/gcc/x86_64-redhat-linux/4.0.2/../../../../lib64/crt1.o
   /usr/lib/gcc/x86_64-redhat-linux/4.0.2/../../../../lib64/crti.o
   /usr/lib/gcc/x86_64-redhat-linux/4.0.2/crtbegin.o

   -L/usr/lib/gcc/x86_64-redhat-linux/4.0.2
   -L/usr/lib/gcc/x86_64-redhat-linux/4.0.2
   -L/usr/lib/gcc/x86_64-redhat-linux/4.0.2/../../../../lib64
   -L/usr/lib/gcc/x86_64-redhat-linux/4.0.2/../../.. -L/lib/../lib64
   -L/usr/lib/../lib64 /tmp/ccgaawQ2.o

   -lstdc++
   -lm
   -lgcc_s
   -lgcc
   -lc
   -lgcc_s
   -lgcc

   /usr/lib/gcc/x86_64-redhat-linux/4.0.2/crtend.o
   /usr/lib/gcc/x86_64-redhat-linux/4.0.2/../../../../lib64/crtn.o

It sounds plausible that this happens because libstdc++ may sometimes need
it, so the remaining question is why -Wl,--as-needed is not the default.