revsetbenchmark: track some simple use of "only"
The only revset is quite useful and has various possible optimisation. tracking
its timing seems useful.
--- a/contrib/all-revsets.txt Fri Mar 01 05:56:18 2019 +0530
+++ b/contrib/all-revsets.txt Thu Jan 24 09:03:15 2019 -0500
@@ -154,3 +154,6 @@
roots(matching(tip, "author"))
roots(matching(tip, "author")) and -10000:-1
(-10000:-1) and roots(matching(tip, "author"))
+only(max(head()))
+only(max(head()), min(head()))
+only(max(head()), limit(head(), 1, 1))