Clean up FNV hash for MSVC

Signed-off-by: unknown <rick@TSS04.home.tropicalstormsoftware.com>
More uint64 shenanigans

Signed-off-by: unknown <rick@TSS04.home.tropicalstormsoftware.com>
A bit more type safety for Win64

Signed-off-by: unknown <rick@TSS04.home.tropicalstormsoftware.com>