In an adaptive system, inlining might be applied on a few hot methods.
We capture these events as follows. When a callee is inlined into a
caller by an optimizing JIT compiler, the call edge from the caller to
callee is added to the call graph unconditionally. This is a
conservative solution without runtime overhead. Since an inlined call
site is likely executed before its caller becomes hot, the number of
added superfluous edges is modest.