Change size of array equations to 1 if -nfScalarize

This makes many backend modules work for models with arrays.

Belonging to [master]:
  - #2698
  - OpenModelica/OpenModelica-testsuite#1045

Compiler/BackEnd/BackendDAEUtil.mo

@@ -2532,7 +2532,7 @@ algorithm
     // ARRAY_EQUATION
     case BackendDAE.ARRAY_EQUATION(dimSize=dimsize,left=e1,right=e2)
       equation
-        size = List.reduce(dimsize, intMul);
+        size = if Flags.isSet(Flags.NF_SCALARIZE) then List.reduce(dimsize, intMul) else 1;
         lst1 = incidenceRowExp(e1, vars, iRow, functionTree, inIndexType);
         res = incidenceRowExp(e2, vars, lst1, functionTree, inIndexType);
       then