[m-rev.] diff: diagnosing inst mismatches

[Zoltan Somogyi]

I found the need for this improvement while working
on something else.

Zoltan.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.nongnd
Type: application/octet-stream
Size: 1144 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20170419/0c7a3e6d/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.nongnd
Type: application/octet-stream
Size: 21796 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20170419/0c7a3e6d/attachment-0003.obj>