SSA: Update data flow integration and BarrierGuard interface to use GuardValue.

[aschackmull]

This just tweaks the internal api in SSA to support BarrierGuard wrappers from #20121. Semantics and external interfaces remain unchanged.

[Copilot]

Pull Request Overview

This PR updates the SSA data flow integration interface to use a generic GuardValue type instead of boolean for guard expressions. This change refactors the internal API to support wrapper types for barrier guards while maintaining the same external behavior.

• Introduces a GuardValue class as an abstract value type for guard evaluations
• Updates all guard-related predicates to use GuardValue instead of boolean
• Replaces method names to include "Value" prefix (e.g., hasBranchEdge → hasValueBranchEdge)

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
shared/ssa/codeql/ssa/Ssa.qll	Defines the new GuardValue class and updates all guard interface predicates
shared/dataflow/codeql/dataflow/VariableCapture.qll	Implements GuardValue as Void type for variable capture scenarios
rust/ql/lib/codeql/rust/dataflow/internal/SsaImpl.qll	Updates Rust implementation to use Boolean as GuardValue type
ruby/ql/lib/codeql/ruby/dataflow/internal/SsaImpl.qll	Updates Ruby implementation to use Boolean as GuardValue type
javascript/ql/lib/semmle/javascript/dataflow/internal/sharedlib/Ssa.qll	Updates JavaScript SSA implementation with Boolean guard values
javascript/ql/lib/semmle/javascript/dataflow/internal/TaintTrackingPrivate.qll	Updates taint tracking to use Boolean type for guard checks
javascript/ql/lib/semmle/javascript/dataflow/internal/BarrierGuards.qll	Updates barrier guards implementation with Boolean type
java/ql/lib/semmle/code/java/dataflow/internal/SsaImpl.qll	Updates Java implementation to use Guards::GuardValue type
csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImpl.qll	Updates C# implementation to use Boolean as GuardValue type
cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll	Updates C++ SSA internals to use Boolean guard values
cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll	Updates C++ iterator flow to use Void as GuardValue type

[geoffw0]

LGTM (CPP, Rust). I'm on the fence about asking for DCA runs, I don't think this should affect correctness or performance but ... I've been wrong before.

[aschackmull]

Dca looks uneventful for all languages - except a weird OOM in sarif export for JS. But I would think that's unlikely to be related to this PR.

[aschackmull]

Looks like the JS dca problem is unrelated - the same thing happened on #19854, which was approved and merged.

[geoffw0]

LGTM.