gsk/gi: new Path api fixes
See commits. Also noticed that GskPathPoint
is exposing the inner union data, is that something that is supposed to be used by the API users ? if so, it would be cool to provide getters of the inner data
<record name="PathPoint" c:type="GskPathPoint" glib:type-name="GskPathPoint" glib:get-type="gsk_path_point_get_type" c:symbol-prefix="path_point">
<doc xml:space="preserve">`GskPathPoint` is an opaque type representing a point on a path.
It can be queried for properties of the path at that point, such as its
tangent or its curvature.
To obtain a `GskPathPoint`, use [method@Gsk.Path.get_closest_point].
Note that `GskPathPoint` structs are meant to be stack-allocated, and
don't a reference to the path object they are obtained from. It is the
callers responsibility to keep a reference to the path as long as the
`GskPathPoint` is used.</doc>
<union name="data" c:type="data">
<field name="f" writable="1">
<array zero-terminated="0" fixed-size="8">
<type name="gfloat" c:type="float"/>
</array>
</field>
<field name="p" writable="1">
<array zero-terminated="0" fixed-size="8">
<type name="gpointer" c:type="gpointer"/>
</array>
</field>
</union>