tst_QDate::startOfDay_endOfDay() and its _data() were in danger of
growing a lot of ugly #if-ery to work round the known limitations of
MS's time-zone API and the backend built on them. Replace the #if-ery
with a flags enum indicating which parts we need to ignore on MS and
limit the #if-ery to how those flags get exercised.
Change-Id: I8657b4fba75f1aef1f3f9374e05f60354dc25e34
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>