If we cannot properly resolve the types we should still set the
accumulator to something so that the type propagator can continue.
Amends commit 6a2308e500
Change-Id: Idf3d093ca877bcf11f6a9a82a9d01ccead19e2cc
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Ulf Hermann