cc/gcc: add option to compile against static libstdc++, for gcc-4.4 and newer

Idea and know-how taken from CodeSourcery build script.

Normal build:
$ ldd arm-unknown-linux-uclibcgnueabi-gcc
linux-gate.so.1 => (0xb77f3000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0xb76e8000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb75a1000)
libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb757a000)
/lib/ld-linux.so.2 (0xb77f4000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb755c000)

CC_STATIC_LIBSTDCXX=y:
$ ldd arm-unknown-linux-uclibcgnueabi-gcc
linux-gate.so.1 => (0xb7843000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb76e6000)
/lib/ld-linux.so.2 (0xb7844000)

I made CC_STATIC_LIBSTDCXX default=y since I think
it is always desirable.

Signed-off-by: Johannes Stezenbach <js@sig21.net>

 --- gcc-4.1.0/libstdc++-v3/include/ext/rope.mps	2006-03-24 01:49:51 +0100

 +++ gcc-4.1.0/libstdc++-v3/include/ext/rope	2006-03-24 01:49:37 +0100

 @@ -59,6 +59,9 @@

  #include <bits/allocator.h>

  #include <ext/hash_fun.h>

 +/* cope w/ index defined as macro, SuSv3 proposal */

 +#undef index

 +

  # ifdef __GC

  #   define __GC_CONST const

  # else

 --- gcc-4.1.0/libstdc++-v3/include/ext/ropeimpl.h.mps	2006-03-24 01:50:04 +0100

 +++ gcc-4.1.0/libstdc++-v3/include/ext/ropeimpl.h	2006-03-24 01:50:28 +0100

 @@ -53,6 +53,9 @@

  #include <ext/memory> // For uninitialized_copy_n

  #include <ext/numeric> // For power

 +/* cope w/ index defined as macro, SuSv3 proposal */

 +#undef index

 +

  _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

    using std::size_t;