Add a `NameId` that is effectively just a wrapper around a `StringId`,
with
some additional predefined values for names that don't correspond to
strings, such as the name of `self` or the function's return slot.
Following up on discussion yesterday regarding this split.
Note, I'm expecting #3341 to do IdentifierId -> NameId in SemIR. It
might be worth adding NameId creation directly to StringStore if you're
content with this setup though.
Building on #3313, start using ValueStore on File. Functions and classes
are straightforward. Types here I present as a borderline case where
maybe we want a more bespoke API, but maybe this is okay? Most other
things probably need a slightly different API, which although I might do
that for a consistent interface, felt more out-of-scope for this change.
Building on #3311, change SemIR to use the SharedValueStore. Since this
removes hermeticity, raw output no longer prints ints, reals, and
strings. TokenizedBuffer accessors are modified to return IDs because
values are often passed through in semantics without needing to read
them.
I would've put SharedValueStores on Context, except for the
GetArrayBoundValue convenience method. I felt awkward removing that, so
it's on File, at least for now. That's then used by the formatter and
Lower too. The flipside of this is that TokenizedBuffer has a
SharedValueStores only for printing, so maybe that's similar enough to
what File is doing.
This doesn't start shifting other SemIR members to ValueStore, but that
seems like a next step.