stream-clone: disable gc for `_entries_walk` duration The number of small container created turn Python in a gc-frenzy that seriously impact performance. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) this-change: 20.88 seconds (-40% from baseline; -15% from previous changes)

= Mercurial XXX =

== New Features ==

== Default Format Change ==

These changes affect newly created repositories (or new clones) done with
Mercurial XXX.

== New Experimental Features ==

== Bug Fixes ==

== Backwards Compatibility Changes ==

== Internal API Changes ==

== Miscellaneous ==