{bp-15120} libc/chdir: chdir/fchdir should not depend on environment variables

[jerpelea]

Summary

This PR will still allow basic shell operations such as cd/ls/pwd to be used even when the environment is disabled.

Impact

RELEASE

Testing

CI

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR summary does not meet the NuttX requirements. It's missing crucial information.

Here's why:

• Insufficient Detail in Summary: While it states the what, it lacks the why and how. Why is this change necessary? Was there a bug? Is it a performance improvement? How does it achieve this functionality? What code was modified?
• Missing Issue References: Are there related issues in either the NuttX or NuttX-apps repositories? These should be linked.
• Incomplete Impact Assessment: "RELEASE" is not sufficient. Each impact category needs a YES/NO answer and a description if YES. For example, even if the user impact is minimal, you still need to state "Impact on user: NO". Consider the impact on the build system, hardware, documentation, security, and compatibility.
• Insufficient Testing Information: "CI" is not enough. While CI testing is important, you need to provide specifics about your local testing. What host did you build on? What target hardware or simulator did you test on? The template specifically requests OS, CPU, compiler, architecture, board, and configuration details. Critically, the "before" and "after" log sections are empty. You must demonstrate that the change works and include evidence.

Example of a better Summary:

This PR fixes a regression introduced in [commit hash or issue #] where basic shell commands (cd, ls, pwd) were unavailable when the user environment was disabled. This change modifies the shell initialization logic in apps/examples/nsh/nsh_main.c to ensure these commands are always registered, regardless of environment settings. This resolves the issue by directly calling the built-in command handlers instead of relying on environment lookups.

This would then be followed by properly filled-out Impact and Testing sections.