When MSVC supports ref-qualified members, we need to ensure that
qstring_compat.cpp can see the non-qualified definitions in qstring.h,
which means no precompiled header.
Alternatively, for a bootstrapped build we could not compile
qstring_compat.cpp or #ifndef the functions.
Change-Id: I8ece34503060f0b4b0f8f2df2fb9b0fb1311e269
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
9c9f609313