vlc_fs: rework the VLC readdir API so it doesn't use dirent on Windows

dirent is not a standard header on Windows. In mingw-w64 it also depends if the CRT is compiled with UNICODE or not.

We can use the native API that is available even in UWP/UAP builds.

A vlc_DIR type is introduced so DIR is not used without dirent API and we can have our own internal representation. This also avoids some dirty casts between DIR and the old win32 structure.

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v4:

• exported vlc_closedir() and vlc_rewinddir() for consistency
• make the win32 vlc_DIR private
• fixes from previous patch orders

changed milestone to %4.0

added Component::Input: file system label

changed the description

added MRStatus::Reviewable label

added 1 commit

• ba5e122d - win32: filesystem: use the native Win32 API to list folder contents

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All these API's are available since Windows XP, so it could be backported to 3.0.

added MRStatus::InReview label and removed MRStatus::Reviewable label

approved this merge request

added 12 commits

• c37e2be4 - modules: use vlc_closedir instead of direct closedir
• deb13856 - core: use vlc_closedir instead of direct closedir
• 0235ded8 - dcp: use the portable opendir API
• 6765a166 - skins2: use the portable opendir API
• e79ea274 - core: use vlc_rewinddir to match vlc_opendir
• a8bca89c - vlc_fs: move up vlc_DIR declaration
• 68dace21 - vlc_fs: always use a custom type for our opendir API's
• e3e57e58 - win32: filesystem: allow GetLogicalDrives() in Win10 RS3 UAP builds
• 2fb9d475 - win32: filesystem: only convert to wide when necessary
• ee7598e4 - win32: filesystem: initialize entry once
• 6ea08931 - win32: filesystem: check the drive letter bitmask is valid
• 57a0c9a9 - win32: filesystem: use the native Win32 API to list folder contents

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resolved all threads

added MRStatus::Acceptable label and removed MRStatus::InReview label

added MRStatus::InReview label and removed MRStatus::Acceptable label

added 15 commits

• 7de608ef - vlc_fs: add vlc_closedir/vlc_rewinddir for all platforms
• 52b573ef - dcp: use the portable opendir API
• 9ec5f7c6 - skins2: use the portable opendir API
• c15c1ce1 - modules: use vlc_closedir instead of direct closedir
• 065e139d - core: use vlc_closedir instead of direct closedir
• e323e976 - core: use vlc_rewinddir to match vlc_opendir
• d0d89d05 - vlc_fs: move up vlc_DIR declaration
• a4033247 - vlc_fs: always use a custom type for our opendir API's
• c22f9f11 - win32: filesystem: allow GetLogicalDrives() in Win10 RS3 UAP builds
• e5c25cba - win32: filesystem: only convert to wide when necessary
• 5c0409f9 - win32: filesystem: initialize entry once
• 58a20f46 - win32: filesystem: check the drive letter bitmask is valid
• a3ffb8ef - win32: filesystem: use the native Win32 API to list folder contents
• 38ba4188 - vlc_fs: export vlc_closedir/vlc_rewinddir
• e527eb97 - vlc_fs: make the internal vlc_DIR type private on Windows

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changed the description