Currently, we shrink classpath snapshots at 2 steps:
- Classpath diffing: Shrink the current classpath snapshot against
the previous lookup symbols
- Classpath snapshot saving: Shrink the current classpath snapshot
against the current lookup symbols
With this commit, the shrinking at the second step is now incremental.
The shrinking at the first step is still non-incremental.
Also visit a class file with ASM once to extract all information we need
in advance, instead of visiting the class file each time some piece of
info is needed.
Hung Nguyen