qtcreator: Take over '-std=...' from CXXFLAGS

If the '-std=' compiler flag is set in CXXFLAGS,
take that over into the .pro files used by
Qt Creator.

This makes ClangCodeModel use the correct std version,
and e.g. know about 'std::string_view' if '-std=gnu++2a'
(or anything else indicating C++17 or higher is supported)
is used and thus avoids unnecessary errors/warnings from
being displayed.

Use a list, so other flags can easily be added later.
(It currently doesn't seem reasonable to me to just pass all
cxxflags though, since .pro files are currently only generated
per top-level module, while C++ flags can differ between
different targets in the same module).

Change-Id: Id3f3e2b9ba77e5220a17fd4796937c816979959a
Reviewed-on: https://gerrit.libreoffice.org/73677
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

0 files changed, 0 insertions, 0 deletions