64-bit curl_off_t no longer gated to off_t patch already committed.
TODO:
* Test it on the broadest combination of platforms and compilers.
- * Old logic based on CURL_SIZEOF_CURL_OFF_T, ENABLE_64BIT, HAVE_LONGLONG,
- has to be revisited and adjusted as appropriate.
+ * Old logic based on CURL_SIZEOF_CURL_OFF_T, still needs some adjusting.
* Enabling and disabling of large file support needs further inspection.
* Test case 557 must pass on all autobuilds.
* System off_t, or equivalent, size must be recorded in curlbuild.h