refactor(libSceLibcInternal): share the statvfs layout and its conversion

fstatvfs kept the guest struct statvfs and the sfs2svfs conversion from
the kernel's statfs to itself. Both move to include/Statvfs.hpp so that
statvfs can convert a volume the same way without opening the path.
Nothing changes for fstatvfs.

core/libs/prx/libSceLibcInternal/FilesystemStatistics.cpp

@@ -1,26 +1,7 @@
 #include "prx/libc/include/general/VabiMacros.hpp"
-#include "prx/libkernel/File/include/KernelStatfs.hpp"
-#include <cstddef>
-#include <cstdint>
+#include "prx/libSceLibcInternal/include/Statvfs.hpp"
 #include <cstring>
 
-struct LibcStatvfs {
-    std::uint64_t f_bavail;
-    std::uint64_t f_bfree;
-    std::uint64_t f_blocks;
-    std::uint64_t f_favail;
-    std::uint64_t f_ffree;
-    std::uint64_t f_files;
-    std::uint64_t f_bsize;
-    std::uint64_t f_flag;
-    std::uint64_t f_frsize;
-    std::uint64_t f_fsid;
-    std::uint64_t f_namemax;
-};
-static_assert(sizeof(LibcStatvfs) == 88);
-static_assert(offsetof(LibcStatvfs, f_bsize) == 48);
-static_assert(offsetof(LibcStatvfs, f_namemax) == 80);
-
 extern "C" int APS5_VABI _fstatfs_nid_postfix(int, KernelStatfs*);
 extern "C" int* APS5_VABI __error_nid_postfix();
 
@@ -34,12 +15,7 @@ extern "C" int APS5_VABI fstatvfs_nid_postfix(int descriptor, LibcStatvfs* outpu
         *error = 14;
         return -1;
     }
-    const LibcStatvfs result{
-        static_cast<std::uint64_t>(volume.f_bavail), volume.f_bfree, volume.f_blocks,
-        static_cast<std::uint64_t>(volume.f_ffree), static_cast<std::uint64_t>(volume.f_ffree), volume.f_files,
-        volume.f_iosize, (volume.f_flags & 1) | ((volume.f_flags & 8) >> 2), volume.f_bsize,
-        0, volume.f_namemax
-    };
+    const LibcStatvfs result = StatvfsFromStatfs(volume);
     std::memcpy(output, &result, sizeof(result));
     *error = saved;
     return 0;

core/libs/prx/libSceLibcInternal/include/Statvfs.hpp

@@ -0,0 +1,34 @@
+#ifndef CORE_LIBS_PRX_LIBSCELIBCINTERNAL_INCLUDE_STATVFS_HPP
+#define CORE_LIBS_PRX_LIBSCELIBCINTERNAL_INCLUDE_STATVFS_HPP
+
+#include "prx/libkernel/File/include/KernelStatfs.hpp"
+#include <cstddef>
+#include <cstdint>
+
+struct LibcStatvfs {
+    std::uint64_t f_bavail;
+    std::uint64_t f_bfree;
+    std::uint64_t f_blocks;
+    std::uint64_t f_favail;
+    std::uint64_t f_ffree;
+    std::uint64_t f_files;
+    std::uint64_t f_bsize;
+    std::uint64_t f_flag;
+    std::uint64_t f_frsize;
+    std::uint64_t f_fsid;
+    std::uint64_t f_namemax;
+};
+static_assert(sizeof(LibcStatvfs) == 88);
+static_assert(offsetof(LibcStatvfs, f_bsize) == 48);
+static_assert(offsetof(LibcStatvfs, f_namemax) == 80);
+
+inline LibcStatvfs StatvfsFromStatfs(const KernelStatfs& volume) {
+    return LibcStatvfs{
+        static_cast<std::uint64_t>(volume.f_bavail), volume.f_bfree, volume.f_blocks,
+        static_cast<std::uint64_t>(volume.f_ffree), static_cast<std::uint64_t>(volume.f_ffree), volume.f_files,
+        volume.f_iosize, (volume.f_flags & 1) | ((volume.f_flags & 8) >> 2), volume.f_bsize,
+        0, volume.f_namemax
+    };
+}
+
+#endif