Rust: Use get(An){Arg,Param} helper predicates

[hvitved]

No description provided.

[Copilot]

Pull Request Overview

This PR refactors various QL modules to use the new helper predicates (getParam, getArg, getAParam, getAnArg) in place of manually traversing ParamList and ArgList.

• Replace calls like getParamList().getParam(n) with getParam(n) (and getArgList().getArg(n) with getArg(n)).
• Swap getParamList().getAParam() for getAParam() and getArgList().getAnArg() for getAnArg().
• Simplify parameterExactAccess and related call sites to use these helpers.

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
CaptureModels.qll	Use c.getParam(...) helper instead of c.getParamList().getParam.
TypeInference.qll	Switch to getParam(0) and getArg(0) helpers for type and args.
Type.qll	Use function.getAParam() rather than function.getParamList().getAParam().
VariableImpl.qll	Simplify parameter pattern checks via getAParam().
CallExprImpl.qll	Replace getArgList().getArg(...) with getArg(...).
ControlFlowGraphImpl.qll	Use getParam(i-1) instead of getParamList().getParam(i-1).
CfgNodes.qll	Swap getArgList().getAnArg() for getAnArg().

[Copilot]

[nitpick] For consistency with other modules, call fp.getAParam() directly instead of via getParamList(). This matches how Function.getAParam() is used above.

Suggested change

	not exists(FnPtrTypeRepr fp | fp.getParamList().getAParam().getPat() = pat)
	not exists(FnPtrTypeRepr fp | fp.getAParam().getPat() = pat)