[PATCH] Do not build libsanitizer also for powerpc*-*-linux*

[Yury Gribov]

> I took that patch and applied it to the gcc sources,
> but I still see the error on ppc:
>...
> [bergner@makalu-lp1 asan]$ LD_LIBRARY_PATH=:/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/gcc:/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/gcc/32:/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/powerpc64-linux/32/libsanitizer/asan/.libs::/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/gcc:/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/gcc/32:/home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/powerpc64-linux/32/libsanitizer/asan/.libs: ldd ./asan-interface-1.exe
> 	linux-vdso32.so.1 =>  (0x00100000)
> 	libm.so.6 => /lib/power8/libm.so.6 (0x0ff00000)
> 	libasan.so.1 => /home/bergner/gcc/build/gcc-fsf-mainline-asan-debug-3/powerpc64-linux/32/libsanitizer/asan/.libs/libasan.so.1 (0x0f930000)

Now check indeed seems to be useful: libasan should be the first library 
in the list when -fsanitize=address flag is present. Are compiler specs 
for Power somehow special?

-Y