[m-rev.] for review: warn about moved trace goals

[Zoltan Somogyi]

For review by anyone. I would like to build on this tomorrow,
so in the absence of a review by then, I intend to commit this
tomorrow lunchtime, and deal with any comments post-commit.
Note: the last attached file in the initial part of the output of
"mmc --debug-modes moved_trace_goal.m", the part that already
shows the problems mentioned in the log message, and which
I would like to fix tomorrow, at least for trace goals.

Zoltan.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.wmtg
Type: application/octet-stream
Size: 3172 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20250505/a9a76171/attachment-0003.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.wmtg
Type: application/octet-stream
Size: 105821 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20250505/a9a76171/attachment-0004.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: moved_trace_goal.debug_modes
Type: application/octet-stream
Size: 9895 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20250505/a9a76171/attachment-0005.obj>