ICC on Windows: Disable ref-qualified member functions in MSVC <= 2013

Like MSVC, ICC on Windows in debug mode always makes calls to
dllexported functions instead of inlining them. Since MSVC 2013 doesn't
know about ref-qualification of member functions, this creates an
incompatibility between DLL creation and DLL use.

Task-number: QTBUG-48349
Change-Id: I42e7ef1a481840699a8dffff14053b594810fb42
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>