Revise TclNREvalObjv so that pre-resolution of the Command by a caller
does not force suppression of exception handling.  Let those be separable
demands.  Aim is to bring TclObjInvoke*() into the fold.
merge trunk
New internal routine TclNRInvoke() - NR-enabled path through the machinery
behind invokehidden commands.
More revisions let multi-interp test case work, but at cost of panics
and segfaults.  Pushing the NRE-envelope.
More progress.  NR-enable [interp] and [$slave], completely with
invokehidden subcommand.  Test suite passes with no errors.
merge trunk
merge trunk
merge trunk
merge trunk
merge trunk
merge trunk
Revise execution trace handling to take account of the new reality in
Tcl 8.6 that callers can pre-resolve a cmdPtr for us.  In that case
a re-resolution in the form of another command name lookup isn't the right
thing.
merge trunk
merge trunk
merge trunk
merge trunk
merge trunk
Add test for Bug 2486550.
Inline TEOV_RunEnterTraces() so its interface can be redesigned.
Exceptions raised from enter traces take priority over re-resolution games.