Add a #define for the inet overlaps operator.

Extracted from pending inet selectivity patch.  The rest of it isn't
quite ready to commit, but we might as well push this part so the patch
doesn't have to track the moving target of pg_operator.h.

src/include/catalog/pg_operator.h

@@ -1154,6 +1154,7 @@ DESCR("is supernet or equal");
 #define OID_INET_SUPEQ_OP		934
 DATA(insert OID = 3552	(  "&&"    PGNSP PGUID b f f 869 869	 16 3552	0 network_overlap networksel networkjoinsel ));
 DESCR("overlaps (is subnet or supernet)");
+#define OID_INET_OVERLAP_OP		3552
 
 DATA(insert OID = 2634 (  "~"	   PGNSP PGUID l f f	  0 869 869 0 0 inetnot - - ));
 DESCR("bitwise not");