SSAT, SSAT16, USAT, USAT16

PKH, SEL
SXTAB, SXTAB16, SXTB, SXTB16, SXTH, SXTAH
UXTAB, UXTAB16, UXTB, UXTB16, UXTH, UXTAH

arm_disasm: Remove unnecessary code

This part of disassembly only determines the opcode, there's no need for offset calculation here.

Disassembler: ARMv6K instructions

Handle invalid `Log::Level::Count`

Videocore: Implement simple vertex caching

This gives a ~2/3 reduction in the amount of vertices that need to be
processed through the vertex loaders and the vertex shader, yielding a
good speedup.

Common: Work around bug in MSVC2015 standard library

Use the UNREACHABLE macro instead of `ASSERT(false, ...);`.

The char16_t/char32_t implementations aren't present in the library and
cause linker errors. This is a known issue that wasn't fixed in VS2015
RTM.

Add a case of `Log::Level::Count` to all switch statements that
dispatch on `Log::Level`.  The case simply asserts `false` and notes
the invalid log level.

Save the path leading where the last file have been loaded

I use two variables to save the path for the ROMs and the symbols.
Use of QSettings to avoid new member variable to the class.
Global settings of QSettings is done in main.

dyncom: Handle the case where PC is the source register for STR/VSTM/VLDM

OpenGL: Add a profiler category measuring framebuffer readback

core: Eliminate some unused variable warnings

citra-qt: Adjust initializer list order

Misc. GPU vertex loading fixes

dyncom: Remove an unused variable

This was used prior to InterpreterTranslate existing.

core: Fix missing prototype warnings

citra-qt: Pass string by const reference

Silences a warning.

am_net: Update function table data

Service/APT: Return proper parameters in GetLockHandle.

Enable linker optimizations in MSVC Release builds

dyncom: Handle left-operand PC correctly for data-processing ops

This is considered deprecated in the ARM manual (using PC as an operand),
however, this is still able to be executed on the MPCore (which I'm quite
sure would be rare to begin with).

SOC:U : Fix WinSock function deprecation 

Update Start menu text to match with the real state of the emulator.