It is easy to check that ILDasm has not been built using .NET (just try to
dissassemble itself), so ILDasm.exe may not be using the Reflection API.

The question is: even in the case that ILDasm would use the Reflection API,
how is it possible to get this:
(as generated from ILDasm)

ldstr ...
call valuetype [System.Windows.Forms]System.Windows.Forms.DialogResult
[System.Windows.Forms]System.Windows.Forms.MessageBox::Show(string)

from this:

MessageBox.Show( "Hello world!" );

It seems to me that the Reflection API does not provide all that info, am I
wrong ?

thanks,

Antonio