* bootstrap/Makefile.am (GUILE_OPTIMIZATIONS): Change to just -O1.
* module/language/tree-il/spec.scm (choose-compiler): Use CPS for -O2
and higher.
* module/system/base/optimize.scm (available-optimizations): CPS for -O2
and higher, but -Oresolve-primitives now at -O1 also.
* module/language/cps/optimize.scm (cps-optimizations):
* module/language/tree-il/optimize.scm (tree-il-optimizations):
* module/system/base/optimize.scm (available-optimizations): Invert the
dependency tree to hold the names and default optimization levels in a
central place instead of in the optimizers. It moves definitions
farther from uses, but it avoids us having to load the CPS optimizer
if we don't need it, which improves bootstrap times.
* module/system/base/optimize.scm: New module.
* module/Makefile.am (SOURCES):
* am/bootstrap.am (SOURCES): Add new module.
* module/language/tree-il/optimize.scm (tree-il-optimizations): Rename
from tree-il-default-optimization-options. Directly specify the
optimization level at which a pass should be enabled.
* module/language/cps/optimize.scm (cps-optimizations): Likewise, rename
from cps-default-optimization-options.
* module/scripts/compile.scm (%options, show-optimization-help): Adapt
to use new module.
