Use a bootstrapped -O0 compiler to compile the -O2 Guile

This reduces total build time to around 30 minutes or so.

* Makefile.am (SUBDIRS): Visit bootstrap/ before module/.

* bootstrap/Makefile.am: New file.

* configure.ac: Generate bootstrap/Makefile.

* meta/uninstalled-env.in (top_builddir): Add bootstrap/ to the
  GUILE_LOAD_COMPILED_PATH.

* module/Makefile.am: Simplify to just sort files in alphabetical order;
  since bootstrap/ was already compiled, we don't need to try to
  optimize compilation order.  Although the compiler will get faster as
  more of the compiler itself is optimized, this isn't a significant
  enough effect to worry about.

bootstrap/Makefile.am

@@ -0,0 +1,152 @@
+## Process this file with automake to produce Makefile.in.
+##
+##  	Copyright (C) 2009, 2010, 2011, 2012, 2013,
+##        2014, 2015 Free Software Foundation, Inc.
+##
+##   This file is part of GUILE.
+##
+##   GUILE is free software; you can redistribute it and/or modify it
+##   under the terms of the GNU Lesser General Public License as
+##   published by the Free Software Foundation; either version 3, or
+##   (at your option) any later version.
+##
+##   GUILE is distributed in the hope that it will be useful, but
+##   WITHOUT ANY WARRANTY; without even the implied warranty of
+##   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+##   GNU Lesser General Public License for more details.
+##
+##   You should have received a copy of the GNU Lesser General Public
+##   License along with GUILE; see the file COPYING.LESSER.  If not,
+##   write to the Free Software Foundation, Inc., 51 Franklin Street,
+##   Fifth Floor, Boston, MA 02110-1301 USA
+
+
+GOBJECTS = $(SOURCES:%.scm=%.go)
+GUILE_WARNINGS = -Wunbound-variable -Warity-mismatch -Wformat
+GUILE_OPTIMIZATIONS = -O1
+nobase_noinst_DATA = $(GOBJECTS) ice-9/eval.go
+CLEANFILES = $(GOBJECTS) ice-9/eval.go
+
+$(GOBJECTS): ice-9/eval.go
+
+VM_TARGETS := system/vm/assembler.go system/vm/disassembler.go
+$(VM_TARGETS): $(top_builddir)/libguile/vm-operations.h
+
+AM_V_GUILEC = $(AM_V_GUILEC_$(V))
+AM_V_GUILEC_ = $(AM_V_GUILEC_$(AM_DEFAULT_VERBOSITY))
+AM_V_GUILEC_0 = @echo "  BOOTSTRAP GUILEC" $@;
+
+vpath %.scm @srcdir@/../module
+
+SUFFIXES = .scm .go
+
+.scm.go:
+	$(AM_V_GUILEC)GUILE_AUTO_COMPILE=0			\
+	$(top_builddir)/meta/uninstalled-env			\
+	guild compile --target="$(host)"                        \
+          $(GUILE_WARNINGS) $(GUILE_OPTIMIZATIONS)              \
+	  -L "$(abs_srcdir)" -L "$(abs_builddir)"		\
+	  -L "$(abs_top_srcdir)/guile-readline"			\
+	  -o "$@" "$<"
+
+# A subset of sources that are used by the compiler.  We can compile
+# these in any order; the order below is designed to hopefully result in
+# the lowest total compile time.
+SOURCES =					\
+  language/cps/intmap.scm			\
+  language/cps/intset.scm			\
+  language/cps/utils.scm			\
+  ice-9/vlist.scm				\
+  srfi/srfi-1.scm				\
+						\
+  language/tree-il.scm				\
+  language/tree-il/analyze.scm			\
+  language/tree-il/canonicalize.scm		\
+  language/tree-il/compile-cps.scm		\
+  language/tree-il/debug.scm			\
+  language/tree-il/effects.scm			\
+  language/tree-il/fix-letrec.scm		\
+  language/tree-il/optimize.scm			\
+  language/tree-il/peval.scm			\
+  language/tree-il/primitives.scm		\
+  language/tree-il/spec.scm			\
+						\
+  language/cps.scm				\
+  language/cps/closure-conversion.scm		\
+  language/cps/compile-bytecode.scm		\
+  language/cps/constructors.scm			\
+  language/cps/contification.scm		\
+  language/cps/cse.scm				\
+  language/cps/dce.scm				\
+  language/cps/effects-analysis.scm		\
+  language/cps/elide-values.scm			\
+  language/cps/licm.scm				\
+  language/cps/peel-loops.scm			\
+  language/cps/primitives.scm			\
+  language/cps/prune-bailouts.scm		\
+  language/cps/prune-top-level-scopes.scm	\
+  language/cps/reify-primitives.scm		\
+  language/cps/renumber.scm			\
+  language/cps/rotate-loops.scm			\
+  language/cps/optimize.scm			\
+  language/cps/simplify.scm			\
+  language/cps/self-references.scm		\
+  language/cps/slot-allocation.scm		\
+  language/cps/spec.scm				\
+  language/cps/specialize-primcalls.scm		\
+  language/cps/split-rec.scm			\
+  language/cps/type-checks.scm			\
+  language/cps/type-fold.scm			\
+  language/cps/types.scm			\
+  language/cps/verify.scm			\
+  language/cps/with-cps.scm			\
+						\
+  language/scheme/spec.scm			\
+  language/scheme/compile-tree-il.scm		\
+  language/scheme/decompile-tree-il.scm		\
+						\
+  language/bytecode.scm				\
+  language/bytecode/spec.scm			\
+						\
+  language/value/spec.scm			\
+						\
+  system/base/pmatch.scm			\
+  system/base/syntax.scm			\
+  system/base/compile.scm			\
+  system/base/language.scm			\
+  system/base/lalr.scm				\
+  system/base/message.scm			\
+  system/base/target.scm			\
+  system/base/types.scm				\
+  system/base/ck.scm				\
+						\
+  ice-9/psyntax-pp.scm				\
+  ice-9/boot-9.scm				\
+  ice-9/r5rs.scm				\
+  ice-9/deprecated.scm				\
+  ice-9/binary-ports.scm			\
+  ice-9/command-line.scm			\
+  ice-9/control.scm				\
+  ice-9/format.scm				\
+  ice-9/getopt-long.scm				\
+  ice-9/i18n.scm				\
+  ice-9/match.scm				\
+  ice-9/networking.scm				\
+  ice-9/posix.scm				\
+  ice-9/rdelim.scm				\
+  ice-9/receive.scm				\
+  ice-9/regex.scm				\
+  ice-9/session.scm				\
+  ice-9/pretty-print.scm			\
+						\
+  system/vm/assembler.scm			\
+  system/vm/debug.scm				\
+  system/vm/disassembler.scm			\
+  system/vm/dwarf.scm				\
+  system/vm/elf.scm				\
+  system/vm/frame.scm				\
+  system/vm/linker.scm				\
+  system/vm/loader.scm				\
+  system/vm/program.scm				\
+  system/vm/vm.scm				\
+  system/foreign.scm