fix: make Nebula Clang-compatible

[mojomex]

PR Type

• Improvement
• Bug Fix

Related Links

• Fixes Bug in EIGEN_ALIGN16 #157
• For reference: the same fix in PCL

Description

This PR moves the EIGEN_ALIGN16 from behind point structs to after the struct keyword, remaining compatible with GCC while enabling compilation with Clang (and enabling usage of all the great Clang tools 🎉)

⚠️ Note: Nebula still does not compile on the newest Clang version (18) due to a tricky error in transport_drivers. The newest version I have tested with is Clang 15.

Review Procedure

The code should still compile on GCC, but now compiles on Clang as well.

Pre-Review Checklist for the PR Author

PR Author should check the checkboxes below when creating the PR.

• Assign PR to reviewer

Checklist for the PR Reviewer

Reviewers should check the checkboxes below before approval.

• Commits are properly organized and messages are according to the guideline
• (Optional) Unit tests have been written for new behavior
• PR title describes the changes

Post-Review Checklist for the PR Author

PR Author should check the checkboxes below before merging.

• All open points are addressed and tracked via issues or tickets

CI Checks

• Build and test for PR: Required to pass before the merge.

[veqcc]

LGTM 👍