* configure.ac:
* Makefile.am (SUBDIRS): Replace bootstrap/ with stage0, stage1, and
stage2.
* am/bootstrap.am: Include all files and all rules.
* meta/build-env.in (GUILE_AUTO_COMPILE): Always turn off
auto-compilation. Take a GUILE_BOOTSTRAP_STAGE argument, which can be
stage0, stage1, stage2, or unset. Adapt the load-compiled path
accordingly.
* meta/uninstalled-env.in: Include .go files from stage2.
* module/Makefile.am: Rework to use boostrap.am.
* module/system/base/optimize.scm (available-optimizations): Punt the
inlinable-exports machinery to -O2.
* stage0/Makefile.am:
* stage1/Makefile.am:
* stage2/Makefile.am: New files.
