This includes:
*Functions operating on long long in <stdlib.h>
*Limits of long long types in <limits.h>
*64-bit types and limits (plus intmax_t and its limits) in <stdint.h>
*New format codes, plus functions operating on intmax_t, in <inttypes.h>
The new stuff is generally conditionalized to only be included if __ORCAC_HAS_LONG_LONG__ is defined, or if the implementation claims to be C99 or later. This allows the headers to remain usable with older versions of ORCA/C, or with any hypothetical "strict C89" mode that might be implemented in the future.