Add the SQLITE_ENABLE_PREUPDATE_HOOK compile-time option.

FossilOrigin-Name: 6634521461e6acff7cc778590e62d57831f9230d
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a15b8bf..d31ed4a 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -829,11 +829,13 @@
   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
   void *pUpdateArg;
   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
   void *pPreUpdateArg;          /* First argument to xPreUpdateCallback */
   void (*xPreUpdateCallback)(   /* Registered using sqlite3_preupdate_hook() */
     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64
   );
   PreUpdate *pPreUpdate;        /* Context for active pre-update callback */
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
 #ifndef SQLITE_OMIT_WAL
   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
   void *pWalArg;