add previously-missing ios646.h

include/iso646.h

+#ifndef _ISO646_H
+#define _ISO646_H
+
+#ifndef __cplusplus
+
+#define and    &&
+#define and_eq &=
+#define bitand &
+#define bitor  |
+#define compl  ~
+#define not    !
+#define not_eq !=
+#define or     ||
+#define or_eq  |=
+#define xor    ^
+#define xor_eq ^=
+
+#endif
+
+#endif