Various code cleanups around java.lang.invoke code. Started out with dead code removal in `jli.MemberName`, then piled on to fix a set of minor inefficiencies (excessive vararg array allocations, unnecessary defensive cloning of parameter arrays etc).
------------- Commit messages: - Restore but rename test*Flags - Various cleanups in java.lang.invoke Changes: https://git.openjdk.org/jdk/pull/11540/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11540&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8298177 Stats: 259 lines in 9 files changed: 18 ins; 184 del; 57 mod Patch: https://git.openjdk.org/jdk/pull/11540.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11540/head:pull/11540 PR: https://git.openjdk.org/jdk/pull/11540
