Tweak m4_wrap to force FIFO or LIFO semantics.
* lib/m4sugar/m4sugar.m4 (m4_wrap): Override M4 implementation.
(m4_wrap_lifo, _m4_wrap): New macros.
* lib/m4sugar/m4sh.m4 (AS_INIT): Combine all cleanup into known
order, prior to m4sugar's.
(_AS_DETECT_BETTER_SHELL): Use cleanup parameter, rather than
m4_wrap.
* lib/autotest/general.m4 (AT_INIT): Combine all cleanup into
known order, prior to m4sh's.
* doc/autoconf.texi (Diagnostic Macros) <m4_fatal>: Document
argument.
(Redefined M4 Macros) <m4_wrap>: Rewrite documentation to match
new behavior.
* tests/m4sh.at (AS_INIT cleanup): New test.
* NEWS: Document the change.
Signed-off-by: Eric Blake <ebb9@byu.net>