largefiles: add lfile argument to updatestandin() for efficiency (API)
Before this patch, updatestandin() takes "standin" argument, and
applies splitstandin() on it to pick out a path to largefile (aka
"lfile" or so) from standin.
But in fact, all callers already knows "lfile". In addition to it,
many callers knows both "standin" and "lfile".
Therefore, making updatestandin() take only one of "standin" or
"lfile" is inefficient.
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..