Function gtk_snapshot_append_outset_shadow

pub unsafe extern "C" fn gtk_snapshot_append_outset_shadow(
    snapshot: *mut GtkSnapshot,
    outline: *const GskRoundedRect,
    color: *const GdkRGBA,
    dx: c_float,
    dy: c_float,
    spread: c_float,
    blur_radius: c_float,
)