Ensure that no code is generated for client requests on x32.
From: Matthias Schwarzott <zzam@gentoo.org>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15526
# define PLAT_amd64_win64 1
#elif defined(__linux__) && defined(__i386__)
# define PLAT_x86_linux 1
-#elif defined(__linux__) && defined(__x86_64__)
+#elif defined(__linux__) && defined(__x86_64__) && !defined(__ILP32__)
# define PLAT_amd64_linux 1
#elif defined(__linux__) && defined(__powerpc__) && !defined(__powerpc64__)
# define PLAT_ppc32_linux 1