Libtool test failure with current master

[Ralf Wildenhues]

bootstraping recent Libtool with current git Autoconf gives this
failure:

  $ make check-local TESTSUITEFLAGS="-k config.lt -v -d -x"
  [...]
  ../../libtool/tests/early-libtool.at:216: $ACLOCAL -I m4
  stderr:
  configure.ac:4: error: m4_divert_require: circular dependency of 
_AS_LINENO_PREPARE
  ../../../autoconf/lib/m4sugar/m4sh.m4:308: AS_REQUIRE is expanded from...
  ../../../autoconf/lib/m4sugar/m4sh.m4:951: _AS_LINENO_PREPARE is expanded 
from...
  ../../../autoconf/lib/m4sugar/m4sh.m4:259: _AS_PREPARE is expanded from...
  m4/libtool.m4:563: LT_OUTPUT is expanded from...
  configure.ac:4: the top level
  autom4te: m4 failed with exit status: 1
  aclocal: autom4te failed with exit status: 1
  stdout:
  ../../libtool/tests/early-libtool.at:216: exit code was 1, expected 0
  67. early-libtool.at:126: 67. config.lt (early-libtool.at:126): FAILED 
(early-libtool.at:216)


LT_OUTPUT creates a script like this:

  cat >"$CONFIG_LT" <<_LTEOF
  #! $SHELL
  # Generated by $as_me.
  # Run this file to recreate a libtool stub with the current configuration.

  lt_cl_silent=false
  SHELL=\${CONFIG_SHELL-$SHELL}
  _LTEOF

  cat >>"$CONFIG_LT" <<\_LTEOF
  AS_SHELL_SANITIZE
  _AS_PREPARE

  exec AS_MESSAGE_FD>&1
  exec AS_MESSAGE_LOG_FD>>config.log
  ...

I understand that it is using undocumented features.  All I ask is that,
before 2.64 is released, this is fixed somehow, in one or both packages.

Thanks,
Ralf