Emulator

Not sure which one but one of the commits between May 7, 2018 and May 8, 2018 broke compatibility with Qt 5.6 LTS.
I noticed it when my build target for openSUSE Leap 42.3 failed:

[ 1289s] [ 82%] Building CXX object Source/Core/UICommon/CMakeFiles/uicommon.dir/X11Utils.cpp.o
[ 1291s] [ 82%] Linking CXX static library libuicommon.a
[ 1291s] [ 82%] Built target uicommon
[ 1291s] Scanning dependencies of target dolphin-nogui
[ 1291s] [ 82%] Building CXX object Source/Core/DolphinNoGUI/CMakeFiles/dolphin-nogui.dir/MainNoGUI.cpp.o
[ 1294s] [ 82%] Linking CXX executable ../../../Binaries/dolphin-emu-nogui
[ 1296s] [ 82%] Built target dolphin-nogui
[ 1296s] Scanning dependencies of target dolphin-emu_automoc
[ 1296s] [ 82%] Automatic moc for target dolphin-emu
[ 1297s] Generating moc_AboutDialog.cpp
[ 1297s] Generating moc_CheatsManager.cpp
[ 1297s] Generating moc_ARCodeWidget.cpp
[ 1297s] Generating moc_CheatWarningWidget.cpp
[ 1297s] Generating moc_ControllersWindow.cpp
[ 1297s] Generating moc_FilesystemWidget.cpp
[ 1297s] home/abuild/rpmbuild/BUILD/dolphin-emu-5.0.20180508+git.a9987588eb/Source/Core/Core/IOS/ES/Formats.:27: Parse error at "HLE"
[ 1297s] AUTOGEN: error: process for /home/abuild/rpmbuild/BUILD/dolphin-emu-5.0.20180508+git.a9987588eb/Source/Core/DolphinQt2/moc_FilesystemWidget.cpp failed:
[ 1297s] home/abuild/rpmbuild/BUILD/dolphin-emu-5.0.20180508+git.a9987588eb/Source/Core/Core/IOS/ES/Formats.:27: Parse error at "HLE"

[...]

[ 1304s] moc failed...
[ 1304s] Source/Core/DolphinQt2/CMakeFiles/dolphin-emu_automoc.dir/build.make:57: recipe for target 'Source/Core/DolphinQt2/CMakeFiles/dolphin-emu_automoc' failed
[ 1304s] make[2]: *** [Source/Core/DolphinQt2/CMakeFiles/dolphin-emu_automoc] Error 1
[ 1304s] CMakeFiles/Makefile2:1686: recipe for target 'Source/Core/DolphinQt2/CMakeFiles/dolphin-emu_automoc.dir/all' failed
[ 1304s] make[1]: *** [Source/Core/DolphinQt2/CMakeFiles/dolphin-emu_automoc.dir/all] Error 2
[ 1304s] Makefile:149: recipe for target 'all' failed
[ 1304s] make: *** [all] Error 2
[ 1304s] error: Bad exit status from /var/tmp/rpm-tmp.FoqJTE (%build)

If not too much work, I'd suggest fixing compatibility with it because this LTS version of Qt5 is supported until at least 2019 and several LTS Linux distributions ships that version (RHEL/CentOS 6 and 7, openSUSE Leap 42.3, Mageia 6.0, and probably several more).