069c920a5c
Use JDK11 with `-Xjdk-release=6` for kotlin-stdlib. Use JDK11 with `-Xjdk-release=7` for kotlin-stdlib-jdk7. This allows dropping JDK6 and JDK7 from our build completely and remove `kotlin.build.isObsoleteJdkOverrideEnabled` #KTI-1220. #KT-57808