This disallows modifying the internal string buffer (which shouldn't be
modified anyhow).

* Virtual Filesystem

* Fix delete bug and documentate

* Review fixes + other stuff

* Fix puyo regression

This reverts commit 77c684c1.

* Add VfsFile and VfsDirectory classes

* Finish abstract Vfs classes

* Implement RealVfsFile (computer fs backend)

* Finish RealVfsFile and RealVfsDirectory

* Finished OffsetVfsFile

* More changes

* Fix import paths

* Major refactor

* Remove double const

* Use experimental/filesystem or filesystem depending on compiler

* Port partition_filesystem

* More changes

* More Overhaul

* FSP_SRV fixes

* Fixes and testing

* Try to get filesystem to compile

* Filesystem on linux

* Remove std::filesystem and document/test

* Compile fixes

* Missing include

* Bug fixes

* Fixes

* Rename v_file and v_dir

* clang-format fix

* Rename NGLOG_* to LOG_*

* Most review changes

* Fix TODO

* Guess 'main' to be Directory by filename

Without this, it's possible to get compilation failures in the (rare) scenario where
a container is used to store a bunch of live IOFile instances, as they may be using
std::move_if_noexcept under the hood. Given these definitely don't throw exceptions
this is also not incorrect to add either.

Most modern Unix environments use 64-bit off_t by default: OpenBSD,
FreeBSD, OS X, and Linux libc implementations such as Musl.

glibc is the lone exception; it can default to 32 bits but this is
configurable by setting _FILE_OFFSET_BITS.

Avoiding the stat64()/fstat64() interfaces is desirable because they
are nonstandard and not implemented on many systems (including
OpenBSD and FreeBSD), and using 64 bits for stat()/fstat() is either
the default or trivial to set up.

src/common/file_util.cpp:79:19: error: variable has incomplete type 'struct stat64'
    struct stat64 file_info;
                  ^
src/common/file_util.cpp:79:12: note: forward declaration of 'stat64'
    struct stat64 file_info;
           ^
src/common/file_util.cpp:99:19: error: variable has incomplete type 'struct stat64'
    struct stat64 file_info;
                  ^
src/common/file_util.cpp:99:12: note: forward declaration of 'stat64'
    struct stat64 file_info;
           ^
src/common/file_util.cpp:342:19: error: variable has incomplete type 'struct stat64'
    struct stat64 buf;
                  ^
src/common/file_util.cpp:342:12: note: forward declaration of 'stat64'
    struct stat64 buf;
           ^
src/common/file_util.cpp:359:19: error: variable has incomplete type 'struct stat64'
    struct stat64 buf;
                  ^
src/common/file_util.cpp:359:12: note: forward declaration of 'stat64'
    struct stat64 buf;
           ^
4 errors generated.

This makes clang-format useful on those.

Also add a bunch of forgotten transitive includes, which otherwise
prevented compilation.

ForeachDirectoryEntry didn't actually do anything with the `recursive`
parameter, and the corresponding callback parameter was shadowing the
actual recursion counters in the user functions.

Fixes #1115.

Also improves the performances of DiskArchive’s directory
implementation a lot, simply by not going through the entire tree
instead of just listing the first level files.

Thanks to JayRoxFox for rebasing this on current master!