add util.samestat function for windows.
windows does not have os.path.samestat, and stat().st_ino is always zero,
so util.samestat always returns false on windows.
#!/bin/sh
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg update 0
echo This is file c1 > c
hg add c
hg commit -m "commit #2" -d "1000000 0"
hg update -m 1
rm b
echo This is file c22 > c
hg commit -m "commit #3" -d "1000000 0"