Instead of using a lemon %fallback directive, have the tokenizer try to figure

out whether an instance of "WINDOW" should be TK_WINDOW or TK_ID.

FossilOrigin-Name: 022079cb0d67be5ac0a50dd9a4d41ee55ce8df681ecd0a544170d75fc8649978

tool/lempar.c

@@ -1068,3 +1068,17 @@ void Parse(
 #endif
   return;
 }
+
+/*
+** Return the fallback token corresponding to canonical token iToken, or
+** 0 if iToken has no fallback.
+*/
+int ParseFallback(int iToken){
+#ifdef YYFALLBACK
+  if( iToken<sizeof(yyFallback)/sizeof(yyFallback[0]) ){
+    return yyFallback[iToken];
+  }
+#endif
+  return 0;
+}
+