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>

 (C) 2007 Yann E. MORIN <yann.morin.1998@anciens.enib.fr>

 License: LGPL v2.1

 Shut off a stupid warning: preffered-stack-boundary must be between 4 ad 12,

 and 2 is not.

 diff -dur glibc-2.5.orig/sysdeps/i386/Makefile glibc-2.5/sysdeps/i386/Makefile

 --- glibc-2.5.orig/sysdeps/i386/Makefile	2005-03-06 01:18:16.000000000 +0100

 +++ glibc-2.5/sysdeps/i386/Makefile	2007-05-27 17:49:37.000000000 +0200

 @@ -36,7 +36,7 @@

  ifeq ($(subdir),csu)

  sysdep-CFLAGS += -mpreferred-stack-boundary=4

  else

 -sysdep-CFLAGS += -mpreferred-stack-boundary=2

 +sysdep-CFLAGS += -mpreferred-stack-boundary=4

  # Likewise, any function which calls user callbacks

  uses-callbacks += -mpreferred-stack-boundary=4

  # Likewise, any stack alignment tests