This change fixes the following compilation error when using clang 8 to cross compile base to powerpc64:
/usr/src/gnu/usr.bin/binutils/libopcodes/../../../../contrib/binutils/opcodes/ppc-dis.c:100:35: error: arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension [-Werror,-Wnull-pointer-arithmetic]
info->private_data = (char *) 0 + dialect;
~~~~~~~~~~ ^
1 error generated.
*** [ppc-dis.o] Error code 1
make[6]: stopped in /usr/src/gnu/usr.bin/binutils/libopcodes
1 error