Upgrade toolchain to 2025-02-11

[thanhnguyen-aws]

Update Rust to nightly-2025-02-11

Upstream PR: rust-lang/rust@ee7dc06#diff-51b3860a8aed92b0e981635d4118d369c49850f5b7acf780d31f5ddd5d5d0bc2

Resolves #3884

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[zhassan-aws]

Can you add a link to the upstream PR that required the change to the Kani code?

Changes seemed sane, but tests are still failing.

[carolynzech]

I did some debugging. The problem is that our parsing logic no longer works. Specifically, the comment above parse_coverage_opaque says this:

kani/kani-compiler/src/codegen_cprover_gotoc/codegen/function.rs

Lines 274 to 281 in 475ea5e

	/// Parse a `CoverageOpaque` item and return the corresponding `CovTerm`:
	/// <https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/coverage/enum.CovTerm.html>
	///
	/// At present, a `CovTerm` can be one of the following:
	/// - `CounterIncrement(<num>)`: A physical counter.
	/// - `ExpressionUsed(<num>)`: An expression-based counter.
	/// - `Zero`: A counter with a constant zero value.
	fn parse_coverage_opaque(coverage_opaque: &Opaque) -> CovTerm {

but the documentation for CovTerm doesn't refer to any of these variants. I think this doc comment was always a typo--CovTerm hasn't been changed in a year and a half, but the linked upstream PR does change the variants of CoverageKind here. I added some debug! statements and determined that coverage_opaque for the failing test contains CoverageKind::VirtualCounter. So I think this parse_coverage_opaque function tries to parse CoverageKinds, but needs to be updated to reflect the new variants of that enum).

@thanhnguyen-aws I pushed a copy of this branch with some debug statements added to this branch so you can pick up debugging from there. (Make sure to remove these statements in your final PR).

[zhassan-aws]

@carolynzech you requested changes on this PR (which is blocking the merge), so I re-requested your review.