- configure: disable pthreads by default on Windows.
- configure: disable detecting `fseeko()` on Windows.
(It exists in mingw-w64 2.0.0 and newer, but it's permanently ignored
in CMake, as this function is never necessary on Windows.)
- extend existing exceptions with their Windows variants.
- `lib/formdata.c`: prioritize `_fseeki64()` over `fseeko()`.
To reduce the difference between Windows builds, which now all use
`_fseeki64()`.
- cmake: perm-enable `HAVE_DIRENT_H` and `HAVE_OPENDIR` for mingw-w64,
to match configure.
Follow-up to bfe54b0e88#13137
This in theory could make the dir listing feature work in mingw-w64
build, but in my tests (on WINE) it failed at the preceding `open()`
call.
- cmake: perm-enable `HAVE_STRINGS_H` and `HAVE_UTIME_H` for mingw-w64,
to match configure. (They are wrappers and make no difference in the build.)
Also:
- configure: sync `USE_MANUAL` macro with cmake, by only setting it for
`src`. Drop checker exception.
- CI: use `--disable-dependency-tracking` in existing jobs.
- CI: install packages before git checkout, in existing jobs.
Closes#14678