Keys should use TyI

[vitiral]

Right now I have a hacky approach to keys where the Bst.key is a "CStr pointer" that sometimes points to a type.

This is no good. I should have a key struct

typedef struct { Slc* name; TyI* tyI;    } Key;

I also should have a BST of all TyI's (and TyI prefixes!) so I am not duplicating them.

[vitiral]

For signatures, most of the allocations happen in scanTyI which currently use g.bbaDict.

This is true in var, inp and stk.

I think I'm interested in anywhere where TyI_asSll is called, as well as anywhere that reserves space for a TyI.

Basic design:

• TyI's should be obtained from a "standard" location. This includes when you are trying to add TyI's onto another type.
• Any use of a TyI will (essentially) be permanently cached. There can be no "temporary" TyIs. This helps simplify the API dramatically as well.
  • We keep the types of even locals, so this is good.