Add lambda support to CHACallGraph

[msridhar]

Fixes #1459

To support lambdas, we re-use logic from the LambdaMethodTargetSelector to handle calls that use invokedynamic. CHACallGraph only includes edges for methods reachable from given entrypoints, and our handling of lambdas adds new synthetic classes to the class hierarchy (representing the classes generated for lambdas). So to ensure a complete call graph, we do a second pass after adding these synthetic classes to recompute call targets. This is probably not the most efficient way to do things, but I'm not sure it's the bottleneck; if we need to optimize in the future we should do so based on profiling.

Note that the handling of lambdas here is very imprecise; every call site of a functional interface method will have an edge to every lambda of that functional interface type. Still, it could be practically useful, e.g., when combined with other heuristic filtering of irrelevant code.

We add new tests, and also fix a couple other minor bugs (e.g., there was no edge before to the synthetic method that invokes class initializers, so it wasn't being processed properly).

[github-actions]

Test Results

  813 files  ± 0    813 suites  ±0   4h 12m 4s ⏱️ + 1m 47s
  739 tests + 3    722 ✅ + 3   17 💤 ±0  0 ❌ ±0 
5 057 runs  +21  4 936 ✅ +21  121 💤 ±0  0 ❌ ±0 

Results for commit a81546d. ± Comparison against base commit 6d62392.

♻️ This comment has been updated with latest results.

[liblit]

Looks good. I suggest a few minor tweaks to improve code and Javadoc style.

[msridhar]

Looks good. I suggest a few minor tweaks to improve code and Javadoc style.

Thanks for the detailed review! All suggestions applied.