Update the rust toolchain to nightly-2023-12-03

[tautschnig]

Changes required due to:

• rust-lang/rust@99ac405b96 Move MetadataLoader{,Dyn} to rustc_metadata.
• rust-lang/rust@c997c6d822 Add more information to stable Instance

Resolves #2911

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.

[celinval]

@tautschnig I pushed a few patches, but we're still not there yet.

1. I pushed a workaround the regression on is_foreign_item. If the fix on the rust side lands before this PR, we could remove the workaround.
2. I revisited the simd fix, and we don't need to change the model at all. The way portable_simd invokes the intrinsic hasn't changed. Only the return value has, which only required a change to the unit test.

The simd harness is still failing though, but it's not related to simd_bitmask model. I removed the model, and the index out of bounds failure still happen. I talked to @adpaco-aws and he kindly agreed to take a look at it. My current hypothesis is that this is an issue with simd_shuffle. I added a harness that only invoke resize of a simd vector, and the same issue happens.

[adpaco-aws]

I've pushed the fix for the simd_shuffle issue in addition to some tests, but I think that the PR is blocked because of the other issue with is_foreign_item:

failures:

---- [expected] expected/issue-2589/issue_2589.rs stdout ----

error: test failed: expected output to contain the line(s):
error: Type `std::string::String` does not implement trait `Dummy`. This is likely because `original` is used as a stub but its generic bounds are not being met.
status: exit status: 1
command: "kani" "/home/ubuntu/kani/tests/expected/issue-2589/issue_2589.rs" "-Z" "stubbing"
stdout:
------------------------------------------
Kani Rust Verifier 0.42.0 (standalone)
error: /home/ubuntu/kani/target/kani/bin/kani-compiler exited with status exit status: 101

------------------------------------------
stderr:
------------------------------------------
warning: function `stub` is never used
  --> /home/ubuntu/kani/tests/expected/issue-2589/issue_2589.rs:12:4
   |
12 | fn stub<T: Dummy>() {
   |    ^^^^
   |
   = note: `#[warn(dead_code)]` on by default

warning: 1 warning emitted

warning: function `stub` is never used
  --> /home/ubuntu/kani/tests/expected/issue-2589/issue_2589.rs:12:4
   |
12 | fn stub<T: Dummy>() {
   |    ^^^^
   |
   = note: `#[warn(dead_code)]` on by default

thread 'rustc' panicked at compiler/rustc_smir/src/rustc_smir/builder.rs:63:17:
internal error: entered unreachable code: Failed to evaluate instance constant: Unevaluated(UnevaluatedConst { def: DefId(0:6 ~ issue_2589[bc6b]::Dummy::TRUE), args: [std::string::String], promoted: None }, bool)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Kani unexpectedly panicked during compilation.
Please file an issue here: https://github.com/model-checking/kani/issues/new?labels=bug&template=bug_report.md

[Kani] no current codegen item.
[Kani] no current codegen location.
warning: 1 warning emitted


------------------------------------------



failures:
    [expected] expected/issue-2589/issue_2589.rs

test result: FAILED. 206 passed; 1 failed; 2 ignored; 0 measured; 0 filtered out; finished in 44.78s

Some tests failed in compiletest suite=expected mode=expected host=(none) target=(none)

I'm guessing the workaround doesn't take this case into account? I've also tried to push the toolchain pointer to nightly-2023-12-07 but that doesn't solve this issue: I'm getting the same error in addition to two more.

[adpaco-aws]

Actually, it looks like the perf suite is failing as well... For a different reason:

VERIFICATION:- FAILED
Verification Time: 28.527027s

Summary:
Verification failed for - fmt_u8
Verification failed for - fmt_i8
Complete - 0 successfully verified harnesses, 2 failures, 2 total.

------------------------------------------
stderr:
------------------------------------------
   Compiling format v0.1.0 (/home/runner/work/kani/kani/tests/perf/format)
    Finished test [unoptimized + debuginfo] target(s) in 0.69s

------------------------------------------



failures:
    [cargo-kani-test] perf/format/expected

test result: FAILED. 13 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 1442.94s

[celinval]

Yeah, unfortunately the fix for the foreign item didn't make it to Dec 7th nightly.

[celinval]

I have a new workaround... I'll push it to the branch in a bit. I am looking at the new failures you mentioned with Dec 7th