Improvements to the hash table used to store symbols in the schema, so that

it works better (requires fewer calls to sqlite3StrICmp()) for large schemas,
and uses less code space.

FossilOrigin-Name: 0318b68c845c84eded757c67f820e1783551574ac9e5670be640c4bfe22a934b

src/hash.h

@@ -60,6 +60,7 @@ struct HashElem {
   HashElem *next, *prev;       /* Next and previous elements in the table */
   void *data;                  /* Data associated with this element */
   const char *pKey;            /* Key associated with this element */
+  unsigned int h;              /* hash for pKey */
 };
 
 /*