tests: add log output after stripping for context for next test

It's not obvious what the repo state will be after stripping some
nodes and obsmarkers, so let's include the log output to make it
easier to follow the test case that comes after.

Differential Revision: https://phab.mercurial-scm.org/D4406

tests/test-rebase-obsolete.t

@@ -1123,6 +1123,23 b' consequence f (descendant of d) is left '
   o  0:b173517d0057 a
   
   $ hg strip -r 8:
+  $ hg log -G -r 'a'::
+  *  7:1143e9adc121 f
+  |
+  | o  6:d60ebfa0f1cb e
+  | |
+  | o  5:027ad6c5830d d'
+  | |
+  x |  4:76be324c128b d (rewritten using replace as 5:027ad6c5830d)
+  |/
+  o  3:a82ac2b38757 c
+  |
+  | o  2:630d7c95eff7 x
+  | |
+  o |  1:488e1b7e7341 b
+  |/
+  o  0:b173517d0057 a
+  
 
 If the rebase set has an obsolete (d) with a successor (d') outside the rebase
 set and none in destination, we still get the divergence warning.