Update includes:
- Changing syntax of `OI/`NI` tags from `<!NI;TAG!>` to `<!TAG{NI}!>`
- Fix some incorrect directives
- Change order of diagnostics in some places
- Remove ignored diagnostics from FIR test data (previously `DIAGNOSTICS` didn't work)
- Update FIR dumps in some places and add `FIR_IDENTICAL` if needed
- Replace all JAVAC_SKIP with SKIP_JAVAC directive
Before this commit, we used same transformers for all modules,
which provoked using same ScopeSession for all modules.
Now we re-create transformers for any new module.
This fixes some problems with incorrect caching in ScopeSession.
NB: this provokes ambiguities in some old FE tests,
mostly they're correct (same as old FE).