use of "Octave:invalid-input-arg" as warning id

[Carlo De Falco]

Hi,

The ode solvers newly introduced in core raise a warning
with id "Octave:invalid-input-arg" when an otion is not
set in the input to tell the user that the default value 
is being used.

This behaviour seems to have been introduced by this changeset 

$ hg log -r 20631
changeset:   20631:00caf63edcdf
parent:      20629:ab705b42cfd8
user:        Rik <address@hidden>
date:        Fri Oct 16 10:31:02 2015 -0700
summary:     maint: Remove obsolete ODE options from odeset/odeget/ode45.

In order to replace warning id "OdePkg:InvalidArgument" which is
not correct in a core function.

I'm not sure the current behaviour is correct either, though, as

1) "Octave:invalid-input-arg" is listed in the docs as an error_id but not as a 
warning_id
2) the documentation says
'Octave:invalid-input-arg'
     Indicates that a function was called with invalid input arguments.
but actually this warning is raised when no value is beeing supplied.

Any idea how to deal with this cleanly?

c.