Rust: Fix type inference for library parameters

[hvitved]

The old logic relied on parameters having a pattern, which is not the case for parameters extracted from library code.

The updated test output reveals that we do not handle operator calls correctly. For example, i32 implements both Add and Add<Rhs = &i32>, and currently we resolve 1 + 2 to both add methods, which means that 2 will have reverse-propagated type &i32 in addition to i32. Now fixed by #19749.

DCA (finally) looks good; we gain more call targets without sacrificing performance.

[Copilot]

Pull Request Overview

This PR fixes type inference for library parameters by switching from pattern-based inference to using explicit type representations, updates related test expectations for Pin methods, and renames a debug helper to match its new signature.

• Replace inferAnnotatedType on parameter patterns with TypeMention.resolveTypeAt for library parameters
• Adjust modeled dataflow tests and expected outputs to account for into_inner_unchecked
• Rename debugResolveMethodCallExpr to accept MethodCall instead of MethodCallExpr

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
rust/ql/test/library-tests/dataflow/modeled/main.rs	Reorder imports and update test comment for Pin::into_inner_unchecked
rust/ql/test/library-tests/dataflow/modeled/inline-flow.expected	Update expected model entries and edge labels
rust/ql/lib/codeql/rust/internal/TypeInference.qll	Use TypeMention.resolveTypeAt for parameter types and rename debug function signature

Comments suppressed due to low confidence (1)

rust/ql/test/library-tests/dataflow/modeled/main.rs:98

• [nitpick] These two imports from std::pin could be combined into a single statement: use std::pin::{pin, Pin}; for clarity and conciseness.

use std::pin::pin;

[Copilot]

[nitpick] The debug function signature and parameter name changed from MethodCallExpr/mce to MethodCall/mc. Consider updating any related comments or docs to prevent confusion when maintaining this helper.

Suggested change

	Function debugResolveMethodCallExpr(MethodCall mc) {
	Function debugResolveMethodCall(MethodCall mc) {

[aibaars]

LGTM