Add models of various aligned_allocs

[jeongsoolee09]

Add models of aligned_alloc, available in several ways:

1. ::aligned_alloc, defined in stdlib.h: reference
2. std::aligned_alloc, defined in cstdlib: reference
3. bsl::aligned_alloc, defined here.

[Copilot]

Pull request overview

This PR extends the C/C++ allocation modeling to include aligned_alloc across common namespaces (global C, std, and Bloomberg bsl), enabling CodeQL’s allocation reasoning to recognize these APIs as heap allocators that require deallocation.

Changes:

• Add allocation models for ::aligned_alloc, std::aligned_alloc, and bsl::aligned_alloc with the allocation-size argument mapped to parameter index 1.
• Keep existing standard allocation models (malloc, calloc, alloca, etc.) unchanged.

Show a summary per file

File	Description
cpp/ql/lib/ext/allocation/Std.allocation.model.yml	Adds aligned_alloc entries to the allocationFunctionModel extension for global/std/bsl namespaces.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0

[jeongsoolee09]

I have searched for tests of allocationFunctionModel but have not found any.

[jketema]

Thanks for this. One comment below. Running DCA on this before approving.

[geoffw0]

I have searched for tests of allocationFunctionModel but have not found any.

There are some tests in cpp/ql/test/library-tests/allocators (there are also tests for the various memory management queries, and they provide coverage for more of the variant allocators).

[jketema]

I have searched for tests of allocationFunctionModel but have not found any.

There are some tests in cpp/ql/test/library-tests/allocators (there are also tests for the various memory management queries, and they provide coverage for more of the variant allocators).

I don't think we have been consistently adding tests there for each and every allocation function. If only because there are too many of them.

[jketema]

DCA looks ok. There's one new TP result. I don't really understand why this shows up after this change, as aligned_alloc is not being used (it does occur in the codebase), but I don't think it's worth further investigating this.

Thanks for the contribution.