improvements to function handling

- handle some of the builtin functions
- handle named arguments
- check argument type, variability, etc

Author: adrpo

Compiler/NFFrontEnd/NFBinding.mo

@@ -68,6 +68,7 @@ uniontype Binding
   record TYPED_BINDING
     DAE.Exp bindingExp;
     DAE.Type bindingType;
+    DAE.Const variability;
     Integer propagatedDims;
     SourceInfo info;
   end TYPED_BINDING;

Compiler/NFFrontEnd/NFComponent.mo

@@ -240,6 +240,16 @@ uniontype Component
     end match;
   end getAttributes;
 
+  function getBinding
+    input Component component;
+    output NFBinding.Binding b;
+  algorithm
+    b := match component
+      case UNTYPED_COMPONENT() then component.binding;
+      case TYPED_COMPONENT() then component.binding;
+    end match;
+  end getBinding;
+
   function attr2DaeAttr
     input Attributes attr;
     output DAE.Attributes daeAttr;