[clang] [Lifetime Safety] Highlight lifetimebound calls in alias chain diagnostics (PR #206337)

[via cfe-commits]

iitianpushkar wrote:

Hey @Xazax-hun @NeKon69, I have updated the patch with the suggested changes. Please review it once.
Note : 1 check is failing but unrelated to this pr. Maybe some infra side issue.

Summary of the current design:

- `getFunctionCallInfo(Call)` centralizes callee + argument extraction for calls, constructors, member calls, and operator calls. For instance member calls, the implicit object argument is represented as argument 0.
- `getTrackedArgInfo(FD, Args, I)` is the single shared place that decides whether an argument is tracked for Lifetime Safety.
- `getTrackingInfoForCallArg(Call, Source)` is diagnostic-side glue: reporting has alias-chain expressions rather than the original argument index, so this helper finds the matching argument and then calls `getTrackedArgInfo`.

`getTrackedArgInfo` now distinguishes:

- explicit `lifetimebound`
- inferred/heuristic lifetimebound-style tracking
- not tracked

For explicit cases, the note says:

- `because parameter 'x' is marked 'lifetimebound'`
- `because the implicit object parameter is marked 'lifetimebound'`

For inferred cases, the note says:

- `because parameter 'x' is inferred as lifetimebound`
- `because the implicit object parameter is inferred as lifetimebound`

https://github.com/llvm/llvm-project/pull/206337