pastojs: fixed high(dynarr)

compiler/packages/fcl-passrc/src/pasresolver.pp

@@ -14125,6 +14125,19 @@ end;
 
 procedure TPasResolver.BI_LowHigh_OnEval(Proc: TResElDataBuiltInProc;
   Params: TParamsExpr; Flags: TResEvalFlags; out Evaluated: TResEvalValue);
+
+  function IsDynArrayConstExpr(IdentEl: TPasElement): boolean;
+  begin
+    Result:=false;
+    if not (IdentEl is TPasVariable) then exit;
+    if not (TPasVariable(IdentEl).Expr is TPasExpr) then exit;
+
+    if (IdentEl.ClassType=TPasConst) and TPasConst(IdentEl).IsConst then
+      exit(true);
+    if fExprEvaluator.IsConst(Params) then
+      exit(true); // a const refers an initial value
+  end;
+
 var
   Param: TPasExpr;
   ParamResolved: TPasResolverResult;
@@ -14154,8 +14167,7 @@ begin
         // dyn or open array
         if Proc.BuiltIn=bfLow then
           Evaluated:=TResEvalInt.CreateValue(0)
-        else if (ParamResolved.IdentEl is TPasVariable)
-            and (TPasVariable(ParamResolved.IdentEl).Expr is TPasExpr) then
+        else if IsDynArrayConstExpr(ParamResolved.IdentEl) then
           begin
           Expr:=TPasVariable(ParamResolved.IdentEl).Expr;
           if Expr is TArrayValues then