[base] Clean up signedness issues in `ftdbgmem.c'.

Also fix other minor issues.

* src/base/ftdbgmem.c (FT_MemTableRec): Replace all FT_ULong types
with FT_Long for consistency.
(ft_mem_primes): Change type to `FT_Int'.
(ft_mem_closest_prime, ft_mem_table_set): Updated.

(ft_mem_debug_panic, ft_mem_debug_alloc, ft_mem_debug_free,
ft_mem_debug_realloc): Use `static' keyword and fix signedness
warnings where necessary.

(ft_mem_table_resize, ft_mem_table_new, ft_mem_table_destroy,
ft_mem_table_get_nodep, ft_mem_debug_init, FT_DumpMemory): Fix types
and add or remove casts to avoid signedness warnings.
2 files changed