prob/typed: switch to instrument first, typecheck second

This is the wrong order---we would prefer to typecheck first,
instrument second. But for some reason (probably the submod expander
bug) I can't get that order to work. So tell the typechecker about
the names inserted by expansion and hope it doesn't get too confused
by instrumenter rewriting things.
move provide list to main (easier to write type env for macros)
prob/typed: add type env, get more things working

Change instrumenter, internal functions to cooperate with TR better.
update typed examples
instrumenter: pre-expand inserted code for fewer macro steps

This change is just to simplify debugging.