When Qt is configured with `-qreal float`, then we should still compare
QVariants containing floating point values with the full precision of
the stored type, and not cast to qreal (ie. float).
Cast all floating point types up to double, which is the highest-
precision floating point type we support in Qt. This might have a small
performance impact when compiling with `-qreal float`, if the FPU does
not perform well with double-precision floating point values.
We don't test any `-qreal float` configurations in CI, so not adding
a unit test for this.
Fixes: QTBUG-114991
Pick-to: 6.6 6.5 6.2
Change-Id: I198ec2c39913b501ef2fe99ae3048b160baa1fd8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
1fe60cbcc3