Itcl - the [incr Tcl] extension

FinalizeCreateObject converts all TCL_ERROR codes

into reraised [return -level 2]

which is implicitly [return -level 2 -code ok]

which makes no sense at all.

It goes to the trouble of calling Tcl_GetReturnOptions()
then throws it away.  It has some bizarre dance where
the value of "result" is only captured from Tcl_SetReturnOptions()
for certain kinds of classes.

The whole exercise is just a giant red flag that YOU'RE DOING
IT WRONG.

Then up in clazzUnknownBody we have to [catch] the TCL_RETURN
is order to properly convert it back to a TCL_ERROR.

But the whole clazzUnknownBody invocation of handleClass is
also broken -- at least in the case where we're using unknown
in the TclOO style of reacting to an unknown method.  We
react to a missing method by creating a new instance of the
class with the name of that method?  WTF?

Broken broken broken broken.

Commited to branch bug-5ea6971709 a disabling
of this mess.  Running the test suite with the
change reveals only changes to stack trace details
and error messages -- no functional difference at all.

Whatever problem(s) were believed to be addressed by
this ugliness are not demonstrated by the test suite.
I think it's likely they do not exist.

If they do exist, then for goodness sake, lets solve
the real problems and not reach for this again.

A TclOO object is driven by an access command.  Often
we think that command "is" the object.

The access command operates exclusively via subcommands,
and the valid subcommands is determined by all the components
in the definition of the object, its class, inheritance, etc. etc.

$object $sub {*}$args

A TclOO class, including oo::class, is a TclOO object, so it's
driven by the same sort of command.  It follows that instance
creation takes on one of these forms:

    $class create $instanceName

    $class new

In contrast, Itcl casts its instance creation commands in one of the forms:

    $iClass $instanceName

    $iClass #auto

Since Itcl 4 is implemented so that an Itcl class is a TclOO class, this
syntax mismatch has to be addressed.  This is the reason the
clazzUnknownBody does what it does.  To take

    $iClass $instanceName

as an encounter with an undefined method and convert it into instance generation.

It's fine that this is done; the problem is that it is also done in other circumstances
like

    my $unknownMethod

The unknown body to accommodate Itcl instance creation syntax should be
more selective in applying its adaptation.

Fix the "unknown" method of Itcl classes so that it is more selective,
enabling the C++ declaration inspired syntax [$class $instance] without
taking lots of missteps in the presence of unknown methods as well.
Patch takes significant effort to preserve error messages, even when in
my judgment they are sub-par, and better ones would be simpler, just for
sake of compatibility.  This patch leaves test import-2.5 failing due
to another bug [f3a2e7407c].

That other bug is now fixed enough to permit merge
of this bug fix.