tree 61084555b312074fb64d01d33c76afd9afa5b294
parent 9dfb111c251350fb326ed540609163bf1a0bbd88
author cpovirk <cpovirk@google.com> 1616526710 -0700
committer Google Java Core Libraries <java-core-libraries-team+copybara@google.com> 1616526860 -0700

Set `-source 8 -target 8` in the open-source build, and remove Java8Usage.

This is largely a rollback of the original Java8Usage change, but I've modified it in a few ways:

- I set `-source 8 -target 8` in the backport.
- I kept the code to make includes/excludes fully work with maven-compiler-plugin, since that could save us some confusion down the line.
- I incorporated a rollback of the changes to Preconditions from CL 361700569, in which I moved the warning from MoreObjects to Preconditions.
- I added errors to our internal release scripts so that we don't accidentally make a release that drops Java 7 support before we're ready.

Fixes https://github.com/google/guava/issues/5269

PiperOrigin-RevId: 364614257