[Development] moc change to use C++ constructs

[Thiago Macieira]

Re: https://codereview.qt-project.org/c/qt/qtbase/+/417148
(which should integrate, as the integration has now been running for 6 hours)

You should not see any changes, because the code is backwards and forwards 
compatible. The only issue I've found applies only to namespaced Qt builds, 
when the #include moc is inside a namespace instead of its proper position 
outside of them all.

Another thing to note is that whenever you start debugging any Qt application, 
gdb will say:

warning: internal error: string "StringData<3, 12, lots of numbers>" failed to 
be canonicalized

That's because the libstdc++ / libbfd implementation of the C++ demangler is 
limited to 2048 characters of input. This is harmless and you can ignore it. 
It doesn't affect LLVM either.
-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Cloud Software Architect - Intel DCAI Cloud Engineering