Update BVH during fusestatic. Fixes #1069 and #1577.

PiperOrigin-RevId: 631748750
Change-Id: I4e1ae01207568c90fc49bcd7d9f760f5187f1afa

src/user/user_objects.h

@@ -293,6 +293,9 @@ class mjCBody : public mjCBody_, private mjsBody {
   // set explicitinertial to true
   void MakeInertialExplicit();
 
+  // compute the bounding volume hierarchy of the body.
+  void ComputeBVH();
+
   // variables set by user
   mjsBody spec;