Function S2Polygon.getDistanceToBoundary
Return the distance from the given point to the polygon boundary. If the polygon is empty or full, return S1Angle::Infinity() (since the polygon has no boundary). "x" should be unit length.
Return the distance from the given point to the polygon boundary. If the polygon is empty or full, return S1Angle::Infinity() (since the polygon has no boundary). "x" should be unit length.