* Makefile.tpl (configure-stage[+id+]-[+prefix+][+module+],
all-stage[+id+]-[+prefix+][+module+], : Use $(current_stage) instead
of `cat stage_current`. Always provide the `r' and `s' variables.
(clean-stage[+id+]-[+prefix+][+module+]): Likewise, and make it into
a single shell execution.
(configure-[+prefix+][+module+], all-[+prefix+][+module+]): For
bootstrapped modules, make the stage1 module if the build was not
started yet, else build the current stage.
(all-host, all-target): Omit bootstrapped modules (if bootstrapping).
(all-build, all-host, all-target, [+make_target+]-host,
[+make_target+]-target): Do not use \-continued lines.
(target modules): Depend on stage_last, not all-gcc, if bootstrapping.
(current_stage, restrap, stage_last): New.
* Makefile.in (LDFLAGS): Define from autoconf substitution.
* Makefile.in (BOOTSTRAPPING): New.
(quickstrap): New definition if BOOTSTRAPPING=yes.
* Makefile.in (CONFIG_LANGUAGES): Substitute all_selected_languages.
* configure.ac: Substitute all_selected_languages with the languages
that were configured. For all the other variables except
lang_specs_files, include all the languages in the tree.
* configure: Regenerate.
* Makefile.in (stmp-fixinc): Copy includes from the prev-gcc directory,
if there is one. Run the commands to run fixincludes in the same
subshell.
* doc/makefile.texi: Document new makefile targets from toplevel bootstrap.
* doc/install.texi: Document exact conventions for searching target tools.
Document --with-build-time-tools. Document toplevel bootstrap. Document
something more about building an Ada cross-compiler. Don't list GNU Make
requirements which affect all platforms.