Forward box2d asserts to exception, then catch those in the new* functions

src/modules/physics/box2d/wrap_Physics.h

@@ -45,6 +45,8 @@
 #include "wrap_WheelJoint.h"
 #include "wrap_RopeJoint.h"
 
+#define ASSERT_GUARD(A) try { A } catch (love::Exception & e) { return luaL_error(L, e.what()); }
+
 namespace love
 {
 namespace physics