[All] Fixed multiple issues during build on Linux

- Added some fixes introduced by RodoMa92 in PR198

- Lack of AVX2 extension (should be done differently in the future)
- Disable deprecated-volatile warning
- Added missing override in posix EventInfo, ImGui notification class and XContent class
- Removed not used XAudio2.h include in XMP
- Fixed missing switch-case in XObject
- Added fugly template in native_list.h
- Fixed multiple smaller issues

src/xenia/cpu/xex_module.cc

@@ -1136,10 +1136,14 @@ void XexModule::Precompile() {
                                 high_code);
   final_image_sha_.finalize(image_sha_bytes_);
 
-  char fmtbuf[16];
+  char fmtbuf[20];
 
   for (unsigned i = 0; i < 20; ++i) {
+#ifdef XE_PLATFORM_WIN32
     sprintf_s(fmtbuf, "%X", image_sha_bytes_[i]);
+#else
+    snprintf(fmtbuf, sizeof(fmtbuf), "%X", image_sha_bytes_[i]);
+#endif
     image_sha_str_ += &fmtbuf[0];
   }