Type Mismatch error when passing a variant to string type parameter

[ccy]

When compile this script, I encounter Type Mismatch error:

var V: Variant;
begin
  V := ''Test''; 
  UpperCase(V); 
end.

If change V to string, it compile without error:

var V: string;
begin
  V := ''Test''; 
  UpperCase(V); 
end.

The issue happens to changes of uPSCompiler.pas in commit 1cabc17

        else if Tmp.ExpectedType = FAnyString then begin
          Tmp.ExpectedType := GetTypeNo(BlockInfo, tmp.Val);
          if not IsStringOrCharType(Tmp.ExpectedType.BaseType) then
          begin
            MakeError('', ecTypeMismatch, '');
            Cleanup;
            exit;
          end;
        end;