Fix typo in configure, gracefully switch between M0 vs M1, skip
CC32/i686-unknown-linux-gnu-gcc targets if not available, esp. for
non-Guix usage.
* configure (M1): Declare missing variable.
* make.scm (main): all-go, clean-go: New targets.
* GNUmakefile (PHONY_TARGETS): Add them.
(.config.make): New target.
* guile/guix/make.scm (%CC32): Set to #f if not found.
(bin.gcc): Skip if CC not set.
(check-target?, add-target): Skip if target is not set.
* configure (optional): New global.
(BUILD_TRIPLET): Use Guile value.
(check-version): Add keyword argument #:optional.
(main): Make CC optional (--with-courage). Only check for stdio.h,
limits.h if CC is found.
Make CC32 check optional.
* scripts/scripts.make: Skip if CC is not set.
* GNUmakefile (build-scripts): New target
(HELP_TOP): Mention it.
* configure (main): Write GUILE_FOR_BUILD.
* make/bin-mlibc.make: Skip if CC32 is not set.
* make/bin.make: Skip if CC is not set.
* make/install.make (install): Only install $(OUT)/mes.mes if
MES_BOOTSTRAP is set.
* make/mescc-guile.make: Skip if GUILE is not set.
* make/mescc-mes.make: Skip if MES is not set.
* HACKING: write something about
* configure (CC32): Accept arm-* as 32 bit compiler.
(check-compile-header-c, check-header-c): New functions.
(parse-opts): New option: --with-courage.
(main): Check for platform, stdio.h, limits.h.
* GNUmakefile (OUT,QUIET,SUBDIRS): New variables.
include make/common.make
* .gitignore: Remove toplevel targets.
* build-aux/compile-all.scm: Import from GNU Guix.
* configure (gulp-pipe): Check exit status. Actually test for CC,
CC32.
* make/bin.make: New file.
* make/check.make: New file.
* make/clean.make: New file.
* make/common.make: New file.
* make/compile.make: New file.
* make/guile.make: New file.
* make/mescc-guile.make: New file.
* make/mescc-mes.make: New file.
* make/reset.make: New file.
* lib/mlibc.c: Rename from top.
* lib/start.c: Rename from top.
* module/module.make: New file.
* scaffold/scaffold.make: New file.
* scripts/scripts.make: New file.
* src/mes.c: Rename from top.
* src/src.make: New file.
* src/mes.c: Rename from top.
* src/gc..c: Rename from top.
* src/lib.c: Rename from top.
* src/posix.c: Rename from top.
* src/reader.c: Rename from top.
* src/vector.c: Rename from top.
* tests/tests.make: New file.
* guix.scm (%source-dir): New variable.
(git-file?): New function.
(mes): Use them to simplify building/installing from git.
* make/install.make (READMES): Add INSTALL, README.
* (install): Install mescc.scm and read-0-32.mo.
