Set index of clocked partition for FMI Jacobian

There may be multiple indices. Use the max index for now,
resulting in 0 for continuous models.

Belonging to [master]:
  - #2281

Author: rfranke

Compiler/SimCode/SimCodeUtil.mo

@@ -12805,7 +12805,8 @@ algorithm
       // collect algebraic loops and symjacs for FMIDer
       ({contSimJac}, outModelInfo, symJacs) := addAlgebraicLoopsModelInfoSymJacs({contSimJac}, inModelInfo);
       contPartSimDer := SOME(contSimJac);
-      symJacFMI := {contSimJac};
+      // set partition index to number of clocks (max index) for now
+      symJacFMI := {rewriteJacPartIdx(contSimJac, inModelInfo.nSubClocks)};
     else
       contPartSimDer := NONE();
     end if;

Compiler/Template/CodegenCpp.tpl

@@ -12972,7 +12972,7 @@ template functionJac(list<SimEqSystem> jacEquations, String matrixName, Integer
   <<
   void <%classname%>Jacobian::calc<%matrixName%>JacobianColumn()
   {
-    const int clockIndex = <%partIdx%>;
+    <%if intGt(partIdx, 0) then 'const int clockIndex = <%partIdx%>;'%>
     <%varDecls%>
     <%eqns_%>
   }