a68: support for publicized modules

a68: support for publicized modules

This commit adds support for modules publicizing the exports of other
modules.  For example:

  module GRAMP =
      access pub GRAMP_Symbol,
             pub GRAMP_Word,
             pub GRAMP_Alphabet
  def pub string libgramp_version = "1.0";
      skip
  fed

Signed-off-by: Jose E. Marchesi <jemarch@gnu.org>
gcc/algol68/ChangeLog

	* a68-parser-taxes.cc (tax_module_dec): Do not handle
	DEFINING_MODULE_INDICANT.
	* a68-exports.cc (a68_add_module_to_moif): Do not mangle module
	names in module extracts.
	(add_pub_revelations_to_moif): New function.
	(a68_do_exports): Simplify and call add_pub_revelations_to_moif.
	* a68-imports.cc (a68_decode_moifs): Add all decoded moifs to the
	global list TOP_MOIF.
	* a68-parser-extract.cc (extract_revelation): Recurse to import
	extracts from publicized modules.
	(a68_extract_indicants): Do not add symbol table entries for
	defining modules.
	* a68-types.h (struct TAG_T): Remove field EXPORTED.
	(EXPORTED): Remove macro.
	(TOP_MOIF): Define.
	* a68-parser.cc (a68_parser): Initialize global list of moifs.
	(a68_new_tag): Do not initialize EXPORTED.

gcc/testsuite/ChangeLog

	* algol68/execute/modules/module22bar.a68: New test.
	* algol68/execute/modules/module22foo.a68: Likewise.
	* algol68/execute/modules/program-22.a68: Likewise.
	* algol68/compile/modules/program-11.a68: Adjust test to
	publicized modules.
	* algol68/compile/modules/program-error-multiple-delaration-module-1.a68:
	Likewise.