Rust: Add numeric type barriers for three queries

[geoffw0]

Add numeric type barriers for three queries, increasing accuracy. Refines the classes in Builtins.qll somewhat to support this.

[Copilot]

Pull Request Overview

This PR adds numeric type barriers to three security queries (rust/regex-injection, rust/sql-injection, and rust/log-injection) to reduce false positives. The implementation introduces type classification classes in Builtins.qll to distinguish between numeric types (integral and floating-point) and uses these to create taint flow barriers.

Key Changes

• Introduces NumericType, IntegralType, and FloatingPointType class hierarchies in Builtins.qll
• Adds shared barrier classes in a new Barriers.qll module for numeric and integral/boolean types
• Integrates type-based barriers into the three security queries to prevent false positives when user input is converted to numeric types

Reviewed Changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
rust/ql/lib/codeql/rust/frameworks/stdlib/Builtins.qll	Refactors builtin integer and float types to extend new numeric type hierarchy classes
rust/ql/lib/codeql/rust/security/Barriers.qll	Adds new shared barrier classes based on numeric and integral/boolean types
rust/ql/lib/codeql/rust/security/regex/RegexInjectionExtensions.qll	Integrates IntegralOrBooleanTypeBarrier to prevent false positives
rust/ql/lib/codeql/rust/security/SqlInjectionExtensions.qll	Integrates NumericTypeBarrier to prevent false positives
rust/ql/lib/codeql/rust/security/LogInjectionExtensions.qll	Integrates NumericTypeBarrier to prevent false positives
rust/ql/test/query-tests/security/CWE-117/main.rs	Adds test case for numeric data derived from user input
rust/ql/test/query-tests/security/CWE-089/sqlx.rs	Removes spurious alert annotation from numeric test case
rust/ql/test/query-tests/security/CWE-020/main.rs	Adds test case for numeric user input in regex construction
rust/ql/test/library-tests/elements/builtintypes/*	Adds library test for numeric type classification
rust/ql/src/change-notes/2025-10-31-barriers.md	Documents the query improvements
/.expected	Updates test expectations to reflect removed false positives

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[geoffw0]

Changes accepted, DCA run started...

[geoffw0]

DCA LGTM. Ready to merge.