- just legacy - report warning about deprecation
- both - report warning about deprecation of legacy
- no compiler explicitly chosen - error about explicit setting compiler
warn from cli legacy compiler
nowarn flag - kotlin.js.compiler.nowarn
KT-42326
KT-53074
Set first supported version to 1.3
Add property for oldest depecated language version in order to control unsupported ones
Report error on attempts to manually disable language feature from unsupported versions
Update test data, drop compatibility tests for features from unsupported versions
KT-36146 In progress
Ilya Goncharov