Port of: https://github.com/openjdk/panama-foreign/pull/791 which lifts the sharing mechanism for upcall stubs to AbstractLinker.
This also speeds up upcall stub linking: ------------- Commit messages: - update benchmark - update copyright years - 8302346: Lift upcall sharing mechanism to AbstractLinker Changes: https://git.openjdk.org/jdk/pull/12883/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12883&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8303684 Stats: 155 lines in 16 files changed: 54 ins; 34 del; 67 mod Patch: https://git.openjdk.org/jdk/pull/12883.diff Fetch: git fetch https://git.openjdk.org/jdk pull/12883/head:pull/12883 PR: https://git.openjdk.org/jdk/pull/12883
