void *silc_realloc(void *ptr, size_t size);

    Change the size of the memory block indicated by `ptr' to the new
    size of `size' bytes.  The contents of `ptr' will not be changed.
    If `ptr' is NULL the call is equivalent to silc_malloc.  If the
    `size' is zero (0) the call is equivalent to silc_free.  Free the
    memory by calling silc_free.

    The pointer returned to the reallocated memory area might not be
    same as `ptr'.