test-bisect: adapt for Windows

tests/test-bisect.t

@@ -1,5 +1,3 b''
-  $ "$TESTDIR/hghave" system-sh || exit 80
-
   $ hg init
 
 
@@ -461,7 +459,7 b' test bisecting command'
   $ hg bisect --bad 0
   Testing changeset 15:e7fa0811edb0 (31 changesets remaining, ~4 tests)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-  $ hg bisect --command "'`pwd`/script.py' and some parameters"
+  $ hg bisect --command "python \"$TESTTMP/script.py\" and some parameters"
   changeset 15:e7fa0811edb0: good
   changeset 7:03750880c6b5: good
   changeset 3:b53bea5e2fcb: bad
@@ -494,7 +492,7 b' command'
   $ hg bisect --good tip --noupdate
   $ hg bisect --bad 0 --noupdate
   Testing changeset 15:e7fa0811edb0 (31 changesets remaining, ~4 tests)
-  $ hg bisect --command "'`pwd`/script.sh' and some params" --noupdate
+  $ hg bisect --command "sh \"$TESTTMP/script.sh\" and some params" --noupdate
   changeset 15:e7fa0811edb0: good
   changeset 7:03750880c6b5: good
   changeset 3:b53bea5e2fcb: bad