(emerge nextcloud-client) Failure to build qtwebengine-5.12.3 on AMD CPUs?

[russtopia]

While emerging nextcloud-client, which has qtwebengine has a dependency, emerge of the latter fails (see full errors described in external QT bug link below).

In file included from ../../3rdparty/chromium/third_party/skia/third_party/skcms/skcms.cc:1911:
../../3rdparty/chromium/third_party/skia/third_party/skcms/src/Transform_inl.h:537:6: note: ‘template<int I, int B> void clut(const skcms_A2B*, I32x8, I32x8, Fx8*, Fx8*, Fx8*, Fx8)’ previously declared here
  537 | void clut(const skcms_A2B* a2b, I32 ix, I32 stride, F* r, F* g, F* b, F a) {

This likely isn't a Funtoo bug per se; the link below is a bug filed to the QT bug tracker which they closed, blaming GCC itself. Hmmpf.

https://bugreports.qt.io/browse/QTBUG-77402

However: what's a poor Funtoo user on AMD to do, if QT refuses to acknowledge/fix this issue?

Should Funtoo apply a patch or can QT project be convinced to fix upstream?

UPDATE: Fortunately this doesn't block usage of Nextcloud client completely; I can just use the Nextcloud-2.6.2-x86_64.AppImage downloaded from the server's Info page.

Edited January 29, 2020 by russtopia
Edit title wrt. nextcloud-client, added workaround to just use vendor-compiled nextcloud-client