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>

 Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/gentoo/51_all_gcc-3.4-libiberty-pic.patch

 diff -durN gcc-4.3.1.orig/libiberty/Makefile.in gcc-4.3.1/libiberty/Makefile.in

 --- gcc-4.3.1.orig/libiberty/Makefile.in	2007-07-25 08:26:45.000000000 +0200

 +++ gcc-4.3.1/libiberty/Makefile.in	2008-06-10 14:58:02.000000000 +0200

 @@ -225,6 +225,7 @@

  	  $(AR) $(AR_FLAGS) $(TARGETLIB) \

  	    $(REQUIRED_OFILES) $(EXTRA_OFILES) $(LIBOBJS); \

  	  $(RANLIB) $(TARGETLIB); \

 +	  cp $(TARGETLIB) ../ ; \

  	  cd ..; \

  	else true; fi