Use generated "config.h".

Have `configure` generate a "config.h" file to hold the outcomes of
various tests and definitions.  Include that file in C++ files.

Previously, we passed the outcomes of the various configure-time tests
and definitions to the compiler through the command line.

Makefile.in

@@ -104,6 +104,7 @@ DIST_COMMON = $(srcdir)/Makefile.am $(top_srcdir)/configure \
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
  configure.lineno config.status.lineno
 mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = config.h
 CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 AM_V_P = $(am__v_P_@AM_V@)
@@ -141,7 +142,8 @@ am__recursive_targets = \
   $(am__extra_recursive_targets)
 AM_RECURSIVE_TARGETS = $(am__recursive_targets:-recursive=) TAGS CTAGS \
 	cscope distdir dist dist-all distcheck
-am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) $(LISP)
+am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) \
+	$(LISP)config.h.in
 # Read a list of newline-separated strings from the standard input,
 # and print each of them once, without duplicates.  Input order is
 # *not* preserved.
@@ -162,7 +164,8 @@ ETAGS = etags
 CTAGS = ctags
 CSCOPE = cscope
 DIST_SUBDIRS = $(SUBDIRS)
-am__DIST_COMMON = $(srcdir)/Makefile.in $(top_srcdir)/autoconf/compile \
+am__DIST_COMMON = $(srcdir)/Makefile.in $(srcdir)/config.h.in \
+	$(top_srcdir)/autoconf/compile \
 	$(top_srcdir)/autoconf/config.guess \
 	$(top_srcdir)/autoconf/config.sub \
 	$(top_srcdir)/autoconf/install-sh \
@@ -348,7 +351,8 @@ SUBDIRS = \
 EXTRA_DIST = \
 	git-hash.sh
 
-all: all-recursive
+all: config.h
+	$(MAKE) $(AM_MAKEFLAGS) all-recursive
 
 .SUFFIXES:
 am--refresh: Makefile
@@ -385,6 +389,21 @@ $(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ $(am__aclocal_m4_deps)
 	$(am__cd) $(srcdir) && $(ACLOCAL) $(ACLOCAL_AMFLAGS)
 $(am__aclocal_m4_deps):
 
+config.h: stamp-h1
+	@test -f $@ || rm -f stamp-h1
+	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) stamp-h1
+
+stamp-h1: $(srcdir)/config.h.in $(top_builddir)/config.status
+	@rm -f stamp-h1
+	cd $(top_builddir) && $(SHELL) ./config.status config.h
+$(srcdir)/config.h.in: @MAINTAINER_MODE_TRUE@ $(am__configure_deps) 
+	($(am__cd) $(top_srcdir) && $(AUTOHEADER))
+	rm -f stamp-h1
+	touch $@
+
+distclean-hdr:
+	-rm -f config.h stamp-h1
+
 mostlyclean-libtool:
 	-rm -f *.lo
 
@@ -690,7 +709,7 @@ distcleancheck: distclean
 	       exit 1; } >&2
 check-am: all-am
 check: check-recursive
-all-am: Makefile
+all-am: Makefile config.h
 installdirs: installdirs-recursive
 installdirs-am:
 install: install-recursive
@@ -730,8 +749,8 @@ clean-am: clean-generic clean-libtool mostlyclean-am
 distclean: distclean-recursive
 	-rm -f $(am__CONFIG_DISTCLEAN_FILES)
 	-rm -f Makefile
-distclean-am: clean-am distclean-generic distclean-libtool \
-	distclean-tags
+distclean-am: clean-am distclean-generic distclean-hdr \
+	distclean-libtool distclean-tags
 
 dvi: dvi-recursive
 
@@ -793,23 +812,24 @@ ps-am:
 
 uninstall-am:
 
-.MAKE: $(am__recursive_targets) install-am install-strip
+.MAKE: $(am__recursive_targets) all install-am install-strip
 
 .PHONY: $(am__recursive_targets) CTAGS GTAGS TAGS all all-am \
 	am--refresh check check-am clean clean-cscope clean-generic \
 	clean-libtool cscope cscopelist-am ctags ctags-am dist \
 	dist-all dist-bzip2 dist-gzip dist-lzip dist-shar dist-tarZ \
 	dist-xz dist-zip distcheck distclean distclean-generic \
-	distclean-libtool distclean-tags distcleancheck distdir \
-	distuninstallcheck dvi dvi-am html html-am info info-am \
-	install install-am install-data install-data-am install-dvi \
-	install-dvi-am install-exec install-exec-am install-html \
-	install-html-am install-info install-info-am install-man \
-	install-pdf install-pdf-am install-ps install-ps-am \
-	install-strip installcheck installcheck-am installdirs \
-	installdirs-am maintainer-clean maintainer-clean-generic \
-	mostlyclean mostlyclean-generic mostlyclean-libtool pdf pdf-am \
-	ps ps-am tags tags-am uninstall uninstall-am
+	distclean-hdr distclean-libtool distclean-tags distcleancheck \
+	distdir distuninstallcheck dvi dvi-am html html-am info \
+	info-am install install-am install-data install-data-am \
+	install-dvi install-dvi-am install-exec install-exec-am \
+	install-html install-html-am install-info install-info-am \
+	install-man install-pdf install-pdf-am install-ps \
+	install-ps-am install-strip installcheck installcheck-am \
+	installdirs installdirs-am maintainer-clean \
+	maintainer-clean-generic mostlyclean mostlyclean-generic \
+	mostlyclean-libtool pdf pdf-am ps ps-am tags tags-am uninstall \
+	uninstall-am
 
 .PRECIOUS: Makefile
 

bootstrap

@@ -1,5 +1,6 @@
 #!/bin/sh
 
 aclocal -I m4 \
+&& autoheader \
 && automake --gnu --add-missing \
 && autoconf

config.h.in

@@ -0,0 +1,61 @@
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#undef HAVE_INTTYPES_H
+
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#undef HAVE_STDINT_H
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#undef HAVE_STDLIB_H
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#undef HAVE_STRING_H
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#undef HAVE_SYS_STAT_H
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#undef HAVE_SYS_TYPES_H
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#undef HAVE_UNISTD_H
+
+/* Define to the sub-directory where libtool stores uninstalled libraries. */
+#undef LT_OBJDIR
+
+/* Name of package */
+#undef PACKAGE
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the home page for this package. */
+#undef PACKAGE_URL
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
+/* Version number of package */
+#undef VERSION