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 -ru ltrace-0.5.3.org/configure ltrace-0.5.3/configure

 --- ltrace-0.5.3.org/configure	2011-08-21 18:55:15.000000000 +0200

 +++ ltrace-0.5.3/configure	2011-08-21 18:54:46.000000000 +0200

 @@ -15,8 +15,12 @@

  echo $PACKAGE_VERSION

  echo -n "checking HOST_OS... "

 -HOST_OS=$( uname -s )

 -if [ "$HOST_OS" = "Linux" ]

 +if [ -z "$HOST_OS" ] ; then

 +  HOST_OS=$( uname -s )

 +else

 +  echo -n "using preset: "

 +fi

 +if [ "$HOST_OS" = "Linux" -o "$HOST_OS" = "linux" ]

  then

    HOST_OS="linux-gnu"

  fi