add stdint.h

[eendebakpt]

@sercantutar For gcc the div_t structure should be included from stdint.h.

[eendebakpt]

@sercantutar This PR solves the issue for some platforms, but not all. In my code I changed all occurences of lldiv_t with mylldiv_t and added the code

// not all platforms support lldiv_t, so we define our own 
typedef struct _my_lldiv_t
{
    long long quot;
    long long rem;
} my_lldiv_t;

to the top if InfInt.h.