Qt doesn't work if compiled with LTO

It's hard to tell how long this bug has existed for, but I've only recently discovered it.
It's most likely the issue is with gold linker, but I wouldn't be able to provide good information to the Gold linker devs.

So far only myself and one other user have experienced this bug, both on Arch Linux.
If your interested in how Qt 5.9 is built on Arch Linux, the build script is here: https://git.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/qt5-base#n68

Dolphin-emu seems to be aware of this bug: https://github.com/dolphin-emu/dolphin/wiki/Building-With-Qt which mentions that building with lto will break qt.

The console outputs something like the following whenever you try to launch a Qt application built with LTO.

QObject::connect: signal not found in QPAEventDispatcherGlib 
QObject::connect: signal not found in QCommandLinkButton 
QObject::connect: signal not found in QCommandLinkButton 
QObject::connect: signal not found in QPushButton

I've been able to reproduce the issue with: 
https://github.com/RoboJackets/qt-example/tree/completed 

using the following cmake flags:

cmake ../ -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS="-flto" -DCMAKE_C_FLAGS=" -flto" -DCMAKE_CXX_COMPILER=clang

and adding target_link_libraries(example -lstdc++) on line 21 of CMakeLists.txt

It would be great if we could reproduce this on different distros.

Also, would appreciate guidance if this is the wrong component. 

Additional version information: 

Intel i7 4770
KDE Plasma running on X11
Distro-provided Qt 5.9
gcc (GCC) 7.1.1 20170528

clang version 4.0.1 (tags/RELEASE_401/final)

binutils 2.28.0-3 (provider of gold linker)

GNU gold (GNU Binutils 2.28.0.20170506) 1.14

cmake version 3.8.2