Feature request

Feature description

Support macOS (intel and arm64), libraries compile on macOS using clang and run natively.

Implementation considerations

There a number of fairly minor changes required to support macOS 13.4, Xcode 14.3.1.

This branch contains general changes for clang broken out by sub-library to make it easier to cherry-pick changes into a PR.

• https://github.com/srmainwaring/navigation2/tree/prs/pr-humble-clang

This branch contains a couple of additional changes specific to macOS on arm64, they're not suitable for merging as compilation options have just been disabled if they don't work on macOS.

• https://github.com/srmainwaring/navigation2/tree/wips/wip-humble-macos

Both branches target humble as this is the version of ROS 2 I have a native build for on macOS. Can re-target main for a PR if this feature request is accepted.

Figure: rviz running nav2 / humble on macOS, testing off-board control using XRCE-DDS in ArduPilot.