This change also found a few POSIX compliance bugs with errnos. Another
bug was discovered where, on Windows, pread() and pwrite() could modify
the file position in cases where ReadFile() returned an error e.g. when
seeking past the end of file. We also have more tests!
- Implement openpty()
- Add `--assimilate` flag to APE bootloader
- Restore Linux vDSO clock_gettime() support
- Use `$(APE_NO_MODIFY_SELF)` on more programs