Comment # 4 on bug 1092425 from Michal Srb

Created attachment 771790 [details]
Patch for Qt that prevents the issue.

I have found that the issue is caused by `qfloat::operator float()` in
qtbase/src/corelib/global/qfloat16.h.

For some reason the declaration is omitted when building the documentation
using `#ifndef Q_QDOC`, but its definition is there unconditionally. Omitting
the definition prevents the qdoc failure. See the attached patch.

I don't know yet why it behaves differently on x86 and x86_64, perhaps it has
something to do with the body of the method, which is different depending on
the architecture.

Also, even with broken code, it should not crash with assertion failure. So
there must be something broken in either libclang or qdoc, but I did not yet
find what. Perhaps we could use this patch for the time being.