Add sanitizer_linux_x86_64.lo if __x86_64__ is defined by $CC

Since size of "void *" is 4 bytes for x32, check if __x86_64__ is defined
by $CC, instead of

if test x$ac_cv_sizeof_void_p = x8; then

to decide wether sanitizer_linux_x86_64.lo should be used.

	PR sanitizer/82379
	* configure.tgt (SANITIZER_COMMON_TARGET_DEPENDENT_OBJECTS): Set
	to sanitizer_linux_x86_64.lo if __x86_64__ is defined by $CC.

From-SVN: r253441

libsanitizer/ChangeLog

+2017-10-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR sanitizer/82379
+	* configure.tgt (SANITIZER_COMMON_TARGET_DEPENDENT_OBJECTS): Set
+	to sanitizer_linux_x86_64.lo if __x86_64__ is defined by $CC.
+
 2017-10-02  Jakub Jelinek  <jakub@redhat.com>
 
 	* libbacktrace/backtrace-rename.h (backtrace_uncompress_zdebug):

libsanitizer/configure.tgt

@@ -27,6 +27,8 @@ case "${target}" in
 		TSAN_SUPPORTED=yes
 		LSAN_SUPPORTED=yes
 		TSAN_TARGET_DEPENDENT_OBJECTS=tsan_rtl_amd64.lo
+	fi
+	if echo "int x = __x86_64__;" | $CC -c -x c -o /dev/null - > /dev/null 2>&1; then
 		SANITIZER_COMMON_TARGET_DEPENDENT_OBJECTS=sanitizer_linux_x86_64.lo
 	fi
 	;;