posix: don't compare atime when determining if a file has changed
A file's atime might change even if the file itself doesn't change. This might
cause us to invalidate caches more often than necessary.
Before this change, hg add often resulted in the dirstate being parsed twice
on systems that track atime. After this change, it is only parsed once. For a
repository with over 180,000 files, this speeds up hg add from 1.2 seconds to
1.0.
Test the CIA extension
$ cat >> $HGRCPATH <<EOF
> [extensions]
> hgcia=
>
> [hooks]
> changegroup.cia = python:hgext.hgcia.hook
>
> [web]
> baseurl = http://hgserver/
>
> [cia]
> user = testuser
> project = testproject
> test = True
> EOF
$ hg init src
$ hg init cia
$ cd src
$ echo foo > foo
$ hg ci -Amfoo
adding foo
$ hg push ../cia
pushing to ../cia
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
<message>
<generator>
<name>Mercurial (hgcia)</name>
<version>0.1</version>
<url>http://hg.kublai.com/mercurial/hgcia</url>
<user>testuser</user>
</generator>
<source>
<project>testproject</project>
<branch>default</branch>
</source>
<body>
<commit>
<author>test</author>
<version>0:e63c23eaa88a</version>
<log>foo</log>
<url>http://hgserver/rev/e63c23eaa88a</url>
<files><file uri="http://hgserver/file/e63c23eaa88a/foo" action="add">foo</file></files>
</commit>
</body>
<timestamp>0</timestamp>
</message>
$ cat >> $HGRCPATH <<EOF
> strip = 0
> EOF
$ echo bar > bar
$ hg ci -Ambar
adding bar
$ hg push ../cia
pushing to ../cia
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
<message>
<generator>
<name>Mercurial (hgcia)</name>
<version>0.1</version>
<url>http://hg.kublai.com/mercurial/hgcia</url>
<user>testuser</user>
</generator>
<source>
<project>testproject</project>
<branch>default</branch>
</source>
<body>
<commit>
<author>test</author>
<version>1:c0c7cf58edc5</version>
<log>bar</log>
<url>http://hgserver/$TESTTMP/cia/rev/c0c7cf58edc5</url>
<files><file uri="http://hgserver/$TESTTMP/cia/file/c0c7cf58edc5/bar" action="add">bar</file></files>
</commit>
</body>
<timestamp>0</timestamp>
</message>
$ cd ..