interpret: more consistently use ImmTy in operators and casts
The diff in src/tools/miri/src/shims/x86/sse2.rs should hopefully suffice to explain why this is nicer. :)
rename mir::Constant -> mir::ConstOperand, mir::ConstKind -> mir::Const
Also, be more consistent with the `to/eval_bits` methods... we had some that take a type and some that take a size, and then sometimes the one that takes a type is called `bits_for_ty`.
Turns out that `ty::Const`/`mir::ConstKind` carry their type with them, so we don't need to even pass the type to those `eval_bits` functions at all.
However this is not properly consistent yet: in `ty` we have most of the methods on `ty::Const`, but in `mir` we have them on `mir::ConstKind`. And indeed those two types are the ones that correspond to each other. So `mir::ConstantKind` should actually be renamed to `mir::Const`. But what to do with `mir::Constant`? It carries around a span, that's really more like a constant operand that appears as a MIR operand... it's more suited for `syntax.rs` than `consts.rs`, but the bigger question is, which name should it get if we want to align the `mir` and `ty` types? `ConstOperand`? `ConstOp`? `Literal`? It's not a literal but it has a field called `literal` so it would at least be consistently wrong-ish...
``@oli-obk`` any ideas?
move required_consts check to general post-mono-check function
This factors some code that is common between the interpreter and the codegen backends into shared helper functions. Also as a side-effect the interpreter now uses the same `eval` functions as everyone else to get the evaluated MIR constants.
Also this is in preparation for another post-mono check that will be needed for (the current hackfix for) https://github.com/rust-lang/rust/issues/115709: ensuring that all locals are dynamically sized.
I didn't expect this to change diagnostics, but it's just cycle errors that change.
r? `@oli-obk`
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
...and remove it from `PointeeInfo`, which isn't meant for this.
There are still various places (marked with FIXMEs) that assume all pointers
have the same size and alignment. Fixing this requires parsing non-default
address spaces in the data layout string, which will be done in a followup.
Ensure param-env is const before calling `eval_to_valtree`
Other queries call `ParamEnv::with_const` *inside* of the query itself (e.g. `const_eval_global_id_for_typeck`), so this could alternatively be moved into the provider of `eval_to_valtree` instead. I don't have a particularly strong opinion, though *theoretically* caching is better if we make the query keys more constrained.
I'm not exactly sure how this is an effect of the `-Zmir-opt-level=3` flag. Maybe something about the inliner causes us to inline an unevaluated const into a body where it can be evaluated, but where it has not yet been normalized.
This seems likely, since we're inlining `from_fn_1::<{ N / 2 }, _>` in `from_fn_2`, which means that we will need to evaluate that constant during the const prop pass after inlining.
Fixes#104396
