tests/test-execute-bit.t

tests: on windows, run command explicitly in sh for working command substitution

On windows, os.system runs the command in cmd.exe, which does not know command
substitution. To let this work, run the command explicitly in sh.

This fixes the failure of this test on windows.

  $ "$TESTDIR/hghave" execbit || exit 80

  $ hg init
  $ echo a > a
  $ hg ci -Am'not executable'
  adding a

  $ chmod +x a
  $ hg ci -m'executable'
  $ hg id
  79abf14474dc tip

Make sure we notice the change of mode if the cached size == -1:

  $ hg rm a
  $ hg revert -r 0 a
  $ hg debugstate
  n   0         -1 unset               a
  $ hg status
  M a

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg id
  d69afc33ff8a
  $ test -x a && echo executable -- bad || echo not executable -- good
  not executable -- good