GitLab

- simplified memop flags: we NEVER must kill solely Loads or Stores

- remove block flags for now, use block marks for marking blocks
- BugFix: fix analysis for IGNORE Stores
- BugFix: fixed creation of partly reduntant Loads: must be done BEFORE gen/kill
- removed now unused code
- kill unreachable blocks before analysis helps greatly and is simple, as we have
  to collect these data anyway

[r25703]