Repack structs with more than one padding hole

Sizes gained (measured on 64-bit systems)
BezierEase: shrunk 8 bytes
QRegExpCharClass: shrunk 8 bytes
QRegularExpressionPrivate: shrunk 8 bytes
QTimeLinePrivate: shrunk 8 bytes
QUtcTimeZonePrivate: shrunk 8 bytes
QTextStreamPrivate: shrunk 8 bytes
QDirPrivate: shrunk 8 bytes
QFileDevicePrivate: shrunk 8 bytes

Not done:
QRegExpEngine: 18 bytes in 6 holes (you deserve high memory usage if
you're still using QRegExp)
QTextBoundaryFinder: 8 bytes in 2 holes (public class)
QIODevicePrivate: 6 bytes in 2 holes, but there's no gain in packing
QProcessPrivate: too complex and my copy is modified
QThreadData: awaiting change from Marc

Change-Id: I2a388b5ce17dec0dafcef18ed2e80d0379aa7d1e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>