Necessary to support importing file classes annotated @JvmPackageName,
since the actual package fragment they are a part of has the name from
the `package` declaration.
This annotation is currently internal because we only commit to its
support for our own libraries. It will be used to change JVM package
names of declarations in JDK-specific stdlib additions (now called
kotlin-stdlib-jre7/8), both to preserve source compatibility of the old
Kotlin code and to solve the split package problem (KT-19258)
pyos