SaveData: Added some documentation to FormatSaveData

Properly erase/remove a DebuggerObserver

armemu: Narrow the scope of some variables in handle_v6_insn

armemu: Get rid of bitwise parenthesis warnings

GSP_GPU: Shut up FlushDataCache

SystemSaveData: Fixed a typo that was segfaulting

armemu: Set GE flags properly for SSUB16, SADD16, SSAX, and SASX.

armemu: Fix USAT16.

SaveData: Implemented the SystemSaveData archive.

Maybe sometime when we actually implement that

We still don't know what the other parameters do, but they appear to be very similar to those of FormatThisUserSaveData.
Most likely FormatThisUserSaveData is just an alias for FormatSaveData with LowPathType Empty

Combine SSUB16, SADD16, SASX, and SSAX.

It will be stored in the /syssavedata folder. This archive is user by various Services and possibly games via the FS:U service.

armemu: Unset GE flags for UADD8 if results are < 0x100

armemu: Implement UMAAL

Backport more skyeye fixes from 3dmoo

armemu: Fix SSUB16

Kernel: Add missing permissions

FS_U: Implemented the SaveData archive

The savedata for each game is stored in /savedata/<ProgramID> for NCCH files. ELF files and 3DSX files use the folder 0 because they have no ID information

Got rid of the code duplication in File and Directory

Files that deal with the host machine's file system now live in DiskFile, similarly for directories and DiskDirectory and archives with DiskArchive.

FS_U: Use the correct error code when a file wasn't found

Reference manual states these must be set to zero if this case is true.

Broken from the same reason SADD16 was.

The lo part of the result should only be constructed from the lo halfwords of rm and rn.
The hi part of the result should only be constructed from the hi halfwords of rm and rn.

armemu: Fix SADD16

armemu: Join QADD16/QSUB16 and fix saturation clamping.

There's no reason to have these in the outer-most scope.

The lo and hi parts of the result were being constructed as a result of hi and lo halfword intermixing from the rm and rn regs. However the lo part of the result should be constructed only from the lo halfwords of rm and rn, and the hi part of the result should only be constructed from the hi halfwords of rm and rn.