Add CiTrace recording support.

This is exposed in the GUI as a new "CiTrace Recording" widget.

Playback is implemented by a standalone 3DS homebrew application (which only runs reliably within Citra currently; on an actual 3DS it will often crash still).

src/core/CMakeLists.txt

@@ -115,6 +115,7 @@ set(SRCS
             loader/elf.cpp
             loader/loader.cpp
             loader/ncch.cpp
+            tracer/recorder.cpp
             mem_map.cpp
             memory.cpp
             settings.cpp
@@ -243,6 +244,8 @@ set(HEADERS
             loader/elf.h
             loader/loader.h
             loader/ncch.h
+            tracer/recorder.h
+            tracer/tracer.h
             mem_map.h
             memory.h
             memory_setup.h