[NF] Minor fixs

  - Fix wrong type for some discrete builtin functions.
  - Fix binding type matching decision.

Belonging to [master]:
  - #2282

Author: mahge

Compiler/NFFrontEnd/NFCall.mo

@@ -1404,6 +1404,7 @@ protected
     if Type.isComplex(Type.arrayElementType(argty)) then
       Type.COMPLEX(cls=recopnode) := argty;
 
+      // This will fail if it can't find the function.
       fn_ref := Function.lookupFunctionSilent(Absyn.CREF_IDENT("'String'",{}), recopnode);
       fn_ref := Function.instFuncRef(fn_ref, InstNode.info(recopnode));
       candidates := Call.typeCachedFunctions(fn_ref);
@@ -1461,7 +1462,7 @@ protected
   algorithm
     argtycall := typeNormalCall(call, origin, info);
     argtycall := matchTypedNormalCall(argtycall, origin, info);
-    ty := getType(call);
+    ty := getType(argtycall);
     callExp := Expression.CALL(unboxArgs(argtycall));
   end typeDiscreteCall;
 
@@ -1679,7 +1680,7 @@ protected
 
     argtycall as ARG_TYPED_CALL(ComponentRef.CREF(node = fn_node), args, _) := typeNormalCall(call, origin, info);
     argtycall := matchTypedNormalCall(argtycall, origin, info);
-    ty := getType(call);
+    ty := getType(argtycall);
     callExp := Expression.CALL(unboxArgs(argtycall));
 
     {arg} := args;

Compiler/NFFrontEnd/NFTypeCheck.mo

@@ -2134,7 +2134,7 @@ algorithm
 
         (exp, ty, ty_match) := matchTypes(binding.bindingType, comp_ty, binding.bindingExp, true);
 
-        if not isCompatibleMatch(ty_match) then
+        if not isValidBindingMatch(ty_match) then
           Error.addSourceMessage(Error.VARIABLE_BINDING_TYPE_MISMATCH,
             {name, Binding.toString(binding), Type.toString(comp_ty),
              Type.toString(binding.bindingType)}, Binding.getInfo(binding));