Add visit budget checks to IsMonotonicallyIncreasing and ComputeDoesOverflow

[Copilot]

IsMonotonicallyIncreasing and ComputeDoesOverflow lacked the m_nVisitBudget guard that ComputeRange already uses, allowing unbounded recursion cost in pathological cases.

Description

Added early-exit budget checks to both functions, consistent with the existing pattern in ComputeRange:

if (IsOverBudget())
{
    return false;
}
m_nVisitBudget--;

• IsMonotonicallyIncreasing: false is the conservative result ("not proven monotonic"), so this is safe to return when over budget.
• ComputeDoesOverflow: false ("doesn't overflow") is slightly optimistic in isolation, but ComputeRange independently returns Unknown when over budget, which already blocks bounds-check elimination — so no unsound optimization can occur.

Both checks are placed before GetSearchPath()->Set(...) to avoid leaving stale entries in the search path on early exit.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.