This patch enables ZGC on macOS/aarch64. It does three things: 1) Enables building of ZGC on this platform. 2) Adds `os::processor_id()`, which for now always returns 0. 3) Fixes a WX issue in `OptoRuntime::handle_exception_C()`, where the stackwater mark might unnecessarily process a frame when the thread is in WXExec mode. In this case, the we're not touching any oops, so we don't need to process any frames.
Testing: Passes the same tests as macOS/x86_64 (with the exception of pre-existing issues unrelated to ZGC). ------------- Commit messages: - 8265702: ZGC on macOS/aarch64 Changes: https://git.openjdk.java.net/jdk/pull/3609/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3609&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8265702 Stats: 13 lines in 3 files changed: 7 ins; 1 del; 5 mod Patch: https://git.openjdk.java.net/jdk/pull/3609.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3609/head:pull/3609 PR: https://git.openjdk.java.net/jdk/pull/3609
