- Adds an empty prelude.carbon file
- Imports that file in any non-Core package file
- Adds --disable-prelude-import to avoid that
- Adds --exclude-dump-file-prefix to be able to hide files from dumping
- Used to hide core files (we can't do this by package name due to lex
dumps, for example)
- Restructures some tests to not rely on `i32`, particularly `alias`
tests (which rely on a name ref) and tests with no prelude.
I'm adding the framework for switching i32 to calling Int32 in the
prelude, but I'm running into a separate error actually switching over.
So that *mostly* works, but isn't quite ready for prime time. However,
maybe the current state of this PR is still useful to review since it
does a lot of the infrastructure work and adds the %Core everywhere?
`Self` is modeled as a `bind_symbolic_name` with no corresponding value,
for now at least. In the future it might make sense to model it as a new
kind of instruction, or as a `bind_symbolic_name` whose value is a
`param`, but for now we just want it to introduce a symbolic constant.
In order to convert a value like the `Self` of an interface to a type, a
new instruction `facet_type_access` is introduced. This notionally
accesses the "type" field within a facet, converting it from a pair of
(type, witness) into just the type.
Jon Ross-Perkins
Richard Smith