Incorrect bounding rect calculations on Windows

Qt calculates bounding rects incorrectly for a number of fonts that come preinstalled with Windows. This severely breaks my application when the user selects those fonts.

Here's what happens in the attached screenshot:

1. For each font, the bounding rect is calculated using QFontMetricsF::boundingRect(const QString &text)
2. The bounding rect is drawn
3. The baseline of the text is drawn (by definition of the bounding rect, this is the line at y=0)
4. The text is drawn

The first font shows how it should be: the text is tucked properly into the bounding rect and the baseline is at the correct position.

For all other fonts in the example, the text does not align with the bounding rect and/or the baseline.