cc/gcc: diable libsanitizer without NPTL

gcc-4.8 comes with a new library to sanitise memory access:
- heap-, stack-, and global-buffer overflow, use-after-free
- data-races between threads

This library requires some _np parts of the API, which are not
implemented in the (old) LinuxThreads, which is still available
in uClibc.

Since NPTL requires a i486 or above, i386 are stuck with using LT,
which precludes building the libsanitizer.

Disable libsanitizer, a bit like libatomic is.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Niels Penneman <niels@penneman.org>

 diff -durN gcc-4.4.5.orig/libstdc++-v3/include/c_global/cstdio gcc-4.4.5/libstdc++-v3/include/c_global/cstdio

 --- gcc-4.4.5.orig/libstdc++-v3/include/c_global/cstdio	2009-04-10 01:23:07.000000000 +0200

 +++ gcc-4.4.5/libstdc++-v3/include/c_global/cstdio	2010-10-09 23:11:27.000000000 +0200

 @@ -139,7 +139,7 @@

  _GLIBCXX_END_NAMESPACE

 -#if _GLIBCXX_USE_C99

 +#if _GLIBCXX_USE_C99 || defined __UCLIBC__

  #undef snprintf

  #undef vfscanf