Revise the implementation of OP_Once so that it is smaller, faster, and uses

less memory.  This also fixes an obscure bug introduced 3 days ago by check-in
[5990a1bdb4a073].

FossilOrigin-Name: 6bf5ba10d28f1b0a32aa9a560ae3143a1235eadb

src/global.c

@@ -225,7 +225,8 @@ SQLITE_WSD struct Sqlite3Config sqlite3Config = {
 #ifndef SQLITE_OMIT_BUILTIN_TEST
    0,                         /* xTestCallback */
 #endif
-   0                          /* bLocaltimeFault */
+   0,                         /* bLocaltimeFault */
+   0x7ffffffe                 /* iOnceResetThreshold */
 };
 
 /*