configure: streamline Windows large file feature check

configure: streamline Windows large file feature check

Before this patch the `CURL_CHECK_WIN32_LARGEFILE` feature check was
running an `AC_COMPILE` snippet that always succeeded. (except for
Windows CE, which isn't supported in other parts of `./configure` yet.)

The only Windows toolchain autotools supports is mingw. Of them, curl
only supports mingw-w64. All mingw-w64 versions support large files.
This allows to drop the check and assume it supported on Windows. To not
lose Windows CE support, rework that too, without using `AC_COMPILE`.

Drop the feature check altogether for non-Windows targets.

Ref: https://github.com/curl/curl/pull/15968#discussion_r1912158201
Follow-up to 7eb4ddb850d3757ac9e0b60b0198bbb11e83135e #15968

Closes #15971