Refactoring:  Change "pIndex->onError!=OE_None" to use a macro:
"IsUniqueIndex(pIndex)".  Easier to understand that way.

FossilOrigin-Name: e75b26ee357bb3d3c1a539b05d633ebf314726d7
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 5d72295..1aede95 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1720,6 +1720,9 @@
 /* Return true if index X is a PRIMARY KEY index */
 #define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)
 
+/* Return true if index X is a UNIQUE index */
+#define IsUniqueIndex(X)      ((X)->onError!=OE_None)
+
 /*
 ** Each sample stored in the sqlite_stat3 table is represented in memory 
 ** using a structure of this type.  See documentation at the top of the