This should cover:
```
library "lib" api;
import Foo library default;
import library default;
import library "lib";
```
This splits out `PackageName` and `LibraryName` to their own parse nodes
so that checking can ignore them and still get a balanced parse tree
(otherwise, we essentially need to implement handling of the parse nodes
only to remove the identifiers/string literals -- the optional names
mean we can't blindly do that as before). For reference, these nodes
don't need to be handled because CheckParseTree will need to directly
funnel import information along with checked IRs.
As I was working on this, I noticed `import` and `library` syntax needs
to be fixed for how it imports the current package, and for `Main`
libraries. This mostly reflects the current state in its testing.
Otherwise, this should handle most of the errors I could think of:
dependency cycles, redundant imports, etc.
It does not actually deal with the nuances of cross-IR references.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
1. In general, `semantics_ir` -> `sem_ir`, to match the directory name.
2. For the list of `ValueStore`-related accessors on `SemIR::File`, add
them to `check`'s `Context` object, shortening access.
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.
Building on #3214 and #3215, updates sem_ir yaml to be:
```
- filename: name
sem_ir: [ ... ]
```
Also, changes the textual format from `package { ... }` to `file
<filename> { ... }`. My thought on packages there is:
```
file "foo.carbon" {
package MyPackage
...
}
```
The reason for putting the file first is that it's easier if we put what
we're grouping on first, whereas the package is an "annotation" on the
file.
Continuing with #3070. Just a dir and file rename (mostly removing
prefixes, although for parse_tree_fuzzer and parse_tree_file_test I'm
dropping "tree" instead of "parse"). Everything in the parse dir should
be marked as a move.
Continuing along with #3070. Note this is just a file rename, with BUILD
edits; every file previously in semantics/ should show as moved (except
maybe BUILDs, which split).
Jon Ross-Perkins
josh11bandChandler Carruth