Fix setCommandLineOptions with -d=newInst.

- Invalidate the builtin cache if the newInst flag is toggled via
  setCommandLineOptions.
- Call execStatReset in Main.main to make sure the global root is
  always initialized.

Belonging to [master]:
  - OpenModelica/OMCompiler#2067

Author: perost

Compiler/Main/Main.mo

@@ -837,6 +837,7 @@ protected
   GC.ProfStats stats;
   Integer seconds;
 algorithm
+  execStatReset();
   try
   try
     args_1 := init(args);

Compiler/Script/CevalScript.mo

@@ -601,6 +601,8 @@ algorithm
       SCode.Encapsulated encflag;
       SCode.Restriction restr;
       list<list<Values.Value>> valsLst;
+      Boolean new_inst;
+
     case (cache,_,"parseString",{Values.STRING(str1),Values.STRING(str2)},st,_)
       equation
         Absyn.PROGRAM(classes=classes,within_=within_) = Parser.parsestring(str1,str2);
@@ -935,8 +937,15 @@ algorithm
 
     case (_,_,"setCommandLineOptions",{Values.STRING(str)},st,_)
       equation
+        new_inst = Flags.isSet(Flags.SCODE_INST);
         args = System.strtok(str, " ");
         {} = Flags.readArgs(args);
+
+        // Invalidate the builtin cache if the newInst flag was toggled,
+        // so we don't reuse the wrong builtin program.
+        if new_inst <> Flags.isSet(Flags.SCODE_INST) then
+          setGlobalRoot(Global.builtinIndex, {});
+        end if;
       then
         (FCore.emptyCache(),Values.BOOL(true),st);