C++: fix typedef resolution in ArrayType

[IdrissRio]

This PR fixes typedef resolution for ArrayType by overriding the resolveTypedefs predicate to correctly resolve typedefs.

The new tests use type.getATypeNameUse() to restrict output to type names explicitly present in the test source. Without this, the output would include duplicated lines for each ArrayType encountered, such as int[10], increasing test output size unnecessarily and making it "hard" to debug.

The PR includes a change note.

[Copilot]

Pull Request Overview

This PR ensures that ArrayType typedefs are correctly resolved by overriding its resolveTypedefs predicate, updates corresponding tests, and adds a change note.

• Override resolveTypedefs in ArrayType to return a correctly resolved base type and size.
• Add a CodeQL test (ArrayTypedefs.ql) and update expected outputs to cover array typedef resolution.
• Record the behavior change in a change-note.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cpp/ql/lib/semmle/code/cpp/Type.qll	Added resolveTypedefs override in ArrayType to fix typedef resolution.
cpp/ql/test/library-tests/typedefs/ArrayTypedefs.ql	New query selecting ArrayType with resolved typedefs.
cpp/ql/test/library-tests/typedefs/ArrayTypedefs.expected	Updated expected results for array typedef resolution.
cpp/ql/test/library-tests/typedefs/Typedefs1.expected	Extended expected output to include array typedefs in simple cases.
cpp/ql/test/library-tests/typedefs/Typedefs3.expected	Added entries for int_t and float_t resolutions in existing tests.
cpp/ql/lib/change-notes/2025-06-17-arraytype-typedefs.md	Documented the fix for ArrayType typedef resolution.

Comments suppressed due to low confidence (1)

cpp/ql/lib/semmle/code/cpp/Type.qll:1593

• The override for resolveTypedefs in ArrayType sets only the base type and array size but does not propagate qualifiers (e.g., const/volatile) or the VLA flag. Consider invoking super.resolveTypedefs() or explicitly copying qualifiers and isVla() to ensure all modifiers are retained.

  override Type resolveTypedefs() {

[jketema]

Two small comments, otherwise LGTM

[jketema]

I would prefer if we move this test to its own directory, as it's testing resolveTypedefs and not typedefs per se. Given that we don't have any tests for resolveTypedefs, I would just use that for the directory name, so we can add other kinds of resolveTypedefs tests in the future.

[IdrissRio]

Good point! Thank you. I saw different naming conventions for test folders, and I opted for snake_case, as it seems to be the most commonly used.