* Analyse last reads all at once
* Integrate firstWrite analysis
* Small cleanup
* Use sets instead of seqs
* Remove instrTargets
* Reap the benefits
* Implement error diagnostics
* Operate on DFA index for lastRead analysis
* Use mgetOrPut
* Cache alias results
This improves performance by a lot, since many
CFG locations map to a single PNode
* Improve performance
* Improve performance
* Cleanup
* Fix#17025
* Grammar
* Expand testcase
