The check below can fail incorrectly if the buildid ends with '-p'.
! stderr 'compile.* -e .*-p [^z]'
This fix changes regular expressions to '-e.* -p' or '-N.* -p' instead
of '-e .*-p'. '-l' is no longer used because the compiler accepts
multiple flags starting with '-l' ('-e' and '-N' do not have this
problem), so there could be false matches.