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>

scripts/build/cc/gcc.sh

@@ -647,6 +647,9 @@ do_cc_backend() {
         if [ "${CT_THREADS}" = "none" ]; then
             extra_config+=(--disable-libatomic)
         fi
+        if [ "${CT_THREADS}" != "nptl" ]; then
+            extra_config+=(--disable-libsanitizer)
+        fi
     fi
     if [ "${CT_CC_GCC_LIBMUDFLAP}" = "y" ]; then
         extra_config+=(--enable-libmudflap)