VFS: Add VFile.sync for memory vfs
VFS: Add VFile.sync for memory vfs

sergiobenrocha2/mgba,iracigt/mgba,Touched/mgba,mgba-emu/mgba,iracigt/mgba,Iniquitatis/mgba,jeremyherbert/mgba,libretro/mgba,sergiobenrocha2/mgba,AdmiralCurtiss/mgba,sergiobenrocha2/mgba,zerofalcon/mgba,cassos/mgba,matthewbauer/mgba,cassos/mgba,Iniquitatis/mgba,Touched/mgba,AdmiralCurtiss/mgba,Anty-Lemon/mgba,jeremyherbert/mgba,Anty-Lemon/mgba,libretro/mgba,Touched/mgba,jeremyherbert/mgba,fr500/mgba,libretro/mgba,zerofalcon/mgba,MerryMage/mgba,MerryMage/mgba,mgba-emu/mgba,MerryMage/mgba,askotx/mgba,cassos/mgba,matthewbauer/mgba,sergiobenrocha2/mgba,askotx/mgba,sergiobenrocha2/mgba,iracigt/mgba,AdmiralCurtiss/mgba,bentley/mgba,Iniquitatis/mgba,askotx/mgba,zerofalcon/mgba,Anty-Lemon/mgba,Iniquitatis/mgba,fr500/mgba,libretro/mgba,fr500/mgba,Anty-Lemon/mgba,fr500/mgba,mgba-emu/mgba,mgba-emu/mgba,jeremyherbert/mgba,libretro/mgba,bentley/mgba,askotx/mgba,iracigt/mgba