Simplify the `run` macro to avoid sometimes unnecessary dependency
on `TyCtxt`. Instead, users can use the new internal method `tcx()`.
Additionally, extend the macro to accept closures that may capture
variables.
These are non-backward compatible changes, but they only affect
internal APIs which are provided today as helper functions until we
have a stable API to start the compiler.
Add more APIs to retrieve information about types, and add more instance
resolution options.
Make `Instance::body()` return an Option<Body>, since not every instance
might have an available body. For example, foreign instances, virtual
instances, dependencies.
The latest locals() method in stable MIR returns slices instead of vecs.
This commit also includes fixes to the existing tests that previously
referenced the private locals field.
We are not planning to support user generated constant in the
foreseeable future, so we are removing the Fold logic for now in
favor of the Instance::resolve logic.
The Instance::resolve was however incomplete, since we weren't handling
internalizing constants yet. Thus, I added that.
I decided to keep the Const fields private in case we decide to
translate them lazily.
Also consider call and yield as MIR SSA.
The SSA analysis on MIR only considered `Assign` statements as defining a SSA local.
This PR adds assignments as part of a `Call` or `Yield` terminator in that category.
This mainly allows to perform CopyProp on a call return place.
The only subtlety is in the dominance property: the assignment is only complete at the beginning of the target block.
