tests/test-execute-bit.t

tests: use egrep with regular expression branches for compatibility

GNU grep allows you to use "a\|b" in a regular expression to match either
"a" or "b", but at least Solaris grep does not; only egrep allows for that.
And egrep considers "a+" to be "a{1,}" instead of an "a" and a literal plus
sign, so escape that as well.

#require execbit

  $ 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