[win-fdb] stack overflow in hbtrie_insert from multi_readers test

      // read entire key

        uint8_t *docrawkey = alca(uint8_t, HBTRIE_MAX_KEYLEN);

>      uint8_t *dockey = alca(uint8_t, HBTRIE_MAX_KEYLEN);

        uint32_t docrawkeylen, dockeylen, minrawkeylen;

        uint64_t offset;

        int docnchunk, minchunkno, newchunkno, diffchunkno;

 	fdb_extended_test.exe!__chkstk() Line 109	Unknown

>	fdb_extended_test.exe!_hbtrie_insert(hbtrie * trie, void * rawkey, int rawkeylen, void * value, void * oldvalue_out, unsigned char flag) Line 1925	C++

 	fdb_extended_test.exe!hbtrie_insert(hbtrie * trie, void * rawkey, int rawkeylen, void * value, void * oldvalue_out) Line 2228	C++

 	fdb_extended_test.exe!_fdb_wal_flush_func(void * voidhandle, wal_item * item, avl_tree * stale_seqnum_list, avl_tree * kvs_delta_stats) Line 2565	C++

 	fdb_extended_test.exe!_wal_do_flush(wal_item * item, fdb_status (void *, wal_item *, avl_tree *, avl_tree *) * flush_func, void * dbhandle, avl_tree * stale_seqnum_list, avl_tree * kvs_delta_stats) Line 1571	C++

 	fdb_extended_test.exe!_wal_flush(filemgr * file, void * dbhandle, fdb_status (void *, wal_item *, avl_tree *, avl_tree *) * flush_func, unsigned __int64 (void *, wal_item *) * get_old_offset, void (void *, avl_tree *, avl_tree *) * seq_purge_func, void (filemgr *, avl_tree *) * delta_stats_func, wal_flush_items * flush_items, bool by_compactor) Line 1745	C++

 	fdb_extended_test.exe!wal_flush(filemgr * file, void * dbhandle, fdb_status (void *, wal_item *, avl_tree *, avl_tree *) * flush_func, unsigned __int64 (void *, wal_item *) * get_old_offset, void (void *, avl_tree *, avl_tree *) * seq_purge_func, void (filemgr *, avl_tree *) * delta_stats_func, wal_flush_items * flush_items) Line 1773	C++

 	fdb_extended_test.exe!fdb_set(_fdb_kvs_handle * handle, fdb_doc_struct * doc) Line 3829	C++

 	fdb_extended_test.exe!loadDocsWithRandomKeys(_fdb_file_handle * dbfile, _fdb_kvs_handle * db, fdb_doc_struct * * doc, int num_docs) Line 117	C++

 	fdb_extended_test.exe!test_multi_readers(multi_reader_type reader_type, const char * test_name) Line 522	C++

 	fdb_extended_test.exe!run_tests_with_encryption(int encryption) Line 838	C++

 	fdb_extended_test.exe!main() Line 906	C++