Change type of `rehash_threshold' and `pure' fields in hash-tables

Change type of `rehash_threshold' and `pure' fields in hash-tables

* src/lisp.h (struct Lisp_Hash_Table): Change type of
`rehash_threshold' and `pure' fields and move them after `count'.
* src/fns.c (make_hash_table): Change type of `rehash_threshold' and `pure'.
(Fmake_hash_table, Fhash_table_rehash_threshold):
* src/category.c (hash_get_category_set):
* src/xterm.c (syms_of_xterm):
* src/profiler.c (make_log):
* src/print.c (print_object):
* src/alloc.c (purecopy_hash_table, purecopy): Adjust accordingly.