* Optimize String.Concat calls

* Small refactor

* Added test

* Another test

* Fixing tests

* using /noca

* Fixing test

* Fixing tests again

* Minor adjustments from feedback

* Quick fix

* More tests

* Updated baselines + more tests

* Added better way to test IL directly in unit tests

* Moved StringConcat.fs tests

* Removed bad file

* Using FSharpChecker directly

* Added more tests

* Comparing lines for tests

* Better IL check output

* Small cleanup

* Fixed test