Match FUN_1006b140() and related functions (#1623)

* Match on BETA10

* Possible improvement on Matrix4::Swap

* Document entropy build result

* Comments at at Matrix4::Invert

---------

Co-authored-by: jonschz <jonschz@users.noreply.github.com>

LEGO1/lego/legoomni/src/video/legoanimpresenter.cpp

@@ -703,6 +703,9 @@ MxResult LegoAnimPresenter::FUN_1006b140(LegoROI* p_roi)
 	if (p_roi == NULL) {
 		return FAILURE;
 	}
+#ifdef BETA10
+	MxMatrix unused_matrix;
+#endif
 
 	Matrix4* mn = new MxMatrix();
 	assert(mn);