system/gcov: enhance gcov

[W-M-R]

Summary

1. supports generating device-side code coverage
2. adjust gcov configuration name
3. deal compile warming

Impact

Testing

[nuttxpr]

[Experimental Bot, please feedback here]

This PR summary is missing crucial information to determine if it meets NuttX requirements.

Missing Information:

• Specifics on the change:
  • What "device-side code coverage" means and how it's implemented.
  • How the "gcov configuration name" is adjusted and why.
  • What "compile warnings" are addressed and how.
• Impact details: ALL impact sections are empty. We need to understand:
  • What features are added/changed and how users are affected.
  • Build process changes, hardware/architecture implications.
  • Documentation needs, security considerations, compatibility impacts.
• Testing Context:
  • What build hosts and target environments were used for verification?
  • The provided testing log sections are empty. Actual logs are needed.

To meet NuttX requirements, the PR needs to:

1. Expand the Summary: Provide clear, concise explanations of each change.
2. Complete the Impact section: Address ALL bullet points with specifics.
3. Include Testing Details: Specify environments and provide REAL testing logs demonstrating the changes' effects.

[cederom]

CI errors, restarted :-)

[cederom]

Still CI errors :\

[xiaoxiang781216]

Still CI errors :\

since it depends on apache/nuttx#13965, let's merge both together.