This undoes 5672 in favor of a new plan:
Layers 000 - 099 are for running without syntax sugar. We use them for
building syntax-sugar passes.
Layers 100 and up are for running with all syntax sugar.
The layers are arranged in approximate order so more phases rely on earlier
layers than later ones.
I plan to not use intermediate syntax sugar (just sigils without calls,
or sigils and calls without braces) anywhere except in the specific passes
implementing them.
Right now we always build the library before any apps.
Apps are where our syntax sugar translators (sigils, calls, braces) live.
So we can't use sugar in the standard library.
New idea: move all code for SubX phases into the top-level.
Perhaps we should also just build a single file rather than pipeline stages.
But for now we'll build each phase by building up to some specific layer.
This will simplify test_apps and move lots of one-off logic to a more standard
form in test_layers.
I'm also going to reorg existing layers so that we introduce each phase
at a point where it mostly only gets the helpers it needs.
This commit itself is just cleaning up some common strings. Using explicit
names for them streamlines binaries a bit.
Kartik Agaram