`JDK8_JVM_OPTS` is removed from @bazel_tools with Bazel@HEAD

[meteorcloudy]

Breaking change: https://github.com/bazelbuild/bazel/commit/3a0a4f3b6931fbb6303fc98eec63d4434d8aece4#diff-d5fecbfa677024171f4ad5ea60ffb5886360d2069f86cd04300e791f5d6617c8

rules_appengine should stop using JDK8_JVM_OPTS due to the above breaking change.

[meteorcloudy]

/cc @cushon @comius

[cushon]

JDK8_JVM_OPTS is only needed if using JDK 8 to run javac. If this toolchain is just trying to target the Java 8 language level (but not require a JDK 8 javac), then it might be sufficient to just drop the use of JDK8_JVM_OPTS

https://github.com/bazelbuild/rules_appengine/blob/40ec3611f4108df23034281a743132770a40e820/appengine/java_appengine.bzl#L330-L338

[meteorcloudy]

@pmbethe09 is rules_appengine still being maintained?

[pmbethe09]

There has been no active work on this in some time. Unclear if we should try to get support going again.

[meteorcloudy]

ACK, then I'll disable rules_appengine in our downstream for now.