[FS] Done with CreateFile

include/fs/archive_base.hpp

@@ -105,6 +105,12 @@ struct ArchiveSession {
 // Otherwise the fd of the opened file is returned (or nullptr if the opened file doesn't require one)
 using FileDescriptor = std::optional<FILE*>;
 
+enum class CreateFileResult : u32 {
+    Success = 0,
+    AlreadyExists = 0x82044BE,
+    FileTooLarge = 0x86044D2
+};
+
 class ArchiveBase {
 protected:
     using Handle = u32;
@@ -161,6 +167,7 @@ protected:
 public:
     virtual std::string name() = 0;
     virtual u64 getFreeBytes() = 0;
+    virtual CreateFileResult createFile(const FSPath& path, u64 size) = 0;
     // Returns nullopt if opening the file failed, otherwise returns a file descriptor to it (nullptr if none is needed)
     virtual FileDescriptor openFile(const FSPath& path, const FilePerms& perms) = 0;