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>

     1.1 --- a/scripts/build/cc/gcc.sh	Fri Jan 03 17:10:09 2014 +0100
     1.2 +++ b/scripts/build/cc/gcc.sh	Sat Jan 04 01:02:57 2014 +0100
     1.3 @@ -647,6 +647,9 @@
     1.4          if [ "${CT_THREADS}" = "none" ]; then
     1.5              extra_config+=(--disable-libatomic)
     1.6          fi
     1.7 +        if [ "${CT_THREADS}" != "nptl" ]; then
     1.8 +            extra_config+=(--disable-libsanitizer)
     1.9 +        fi
    1.10      fi
    1.11      if [ "${CT_CC_GCC_LIBMUDFLAP}" = "y" ]; then
    1.12          extra_config+=(--enable-libmudflap)