introduces the bootstrap tool src/share/vm/jfr/GenerateJfrFiles.java within the HotSpot tree. Rather than adapting the tool to work with the existing source & target options used for bootstrap tools,
bumped them to 8. In doing so, it broke the ability to build the JDK with the previous version (7).
The lambda constructs & use of StringJoiner in GenerateJfrFiles.java can be easily replaced with Java 7 compatible usage, thus retaining the ability to bootstrap the JDK.