Memory: Always flush whole pages from surface cache

This prevents individual writes touching a cached page, but which don't
overlap the surface, from constantly hitting the surface cache lookup.

VideoCore: Eliminate an unnecessary copy in the drawcall loop

Convert shader JIT to Xbyak

Kernel/IPC: Use Ports and Sessions as the fundamental building block of Inter Process Communication.

Required to be able to use Xbyak in Citra without header conflicts.

CMakeLists: Autodetect clang and only then use libc++

Minor amendment of GSP_GPU::ImportDisplayCaptureInfo code

time_stretch: Add missing #pragma once directive

Unbreak QT-only build after 75ee2f8c

Support mingw cross-compilation

APT::GetStartupArgument: force clear startup argument

The new Qt event syntax allows for regular member functions to be used in
connect(), so explicitly indicating slots isn't necessary.

appendRow takes a QList by const reference, so it doesn't need to be
modifiable.

Makes for more compact code in most places.

If the control was ever passed an explicit parent, a potential memory leak
would happen, as the game list wouldn't be freed.

However, in our case, the game list was placed within a layout, which
automatically performs reparenting, avoiding this issue.

graphics_cmdlist: Minor changes

Puts the TextureInfoWidget definition in the anonymous namespace as well,
as it's only used in the translation unit as well.

Previously there was a split where some of the services were in the
Service namespace and others were not.

* Removed use of raw QTimer* pointer.
* Update to use type-safe QObject::connect.
* getKeyName can be a static local function.
* Prefer to use function arguments instead of member variables.
* Store Qt::Key instead of converting string back into keycode.

audio_core: SelectSink should default to auto if sink_id is invalid