sim/posix: Add APPLE to a build target for sim's configuration using CMake.

[toku-mac]

Summary

• Add macOS support to the hello_rust_cargo CMake build configuration.
• Depends on apps PR: apps:cmake: Add APPLE to a build target for sim's configuration using CMake
• Although the C compiler included in Xcode is named gcc, its actual implementation is clang.

❯ /usr/bin/gcc --version
Apple clang version 21.0.0 (clang-2100.1.1.101)
Target: arm64-apple-darwin25.5.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

About macho_call_saved_init_funcs() Issue

• The issue occurs when save_and_replace_init_funcs() does not appear at the head of __mod_init_func. For example, consider this sequence:

[0] constructor A
[1] save_and_replace_init_funcs
[2] constructor B
...

• Since dyld calls __mod_init_func entries in the order they appear, constructor A has already executed before save_and_replace_init_funcs() is called.
• In this state, the original implementation enters the else branch until it finds save_and_replace_init_funcs(), where it executes g_saved_init_funcs[i - 1] = *fp;.
• With the first entry, i == 0, so i - 1 becomes out-of-bounds when interpreted without sign, or -1 even as an int, resulting in an invalid write to g_saved_init_funcs[-1].
• This leads to either an invalid reference or crash in the macho_call_saved_init_funcs() side.

Impact

• Impact on build: enables building with cargo and cmake.

Testing

I confirm that changes are verified on local setup and works as intended:

• Build Host(s): OS (macOS 26.5), CPU(Apple M1), compiler(Apple clang version 21.0.0)
• Target(s): arch(sim)
• Ensure your PATH environment variable is properly configured to allow execution of: menuconfig, olddefconfig, savedefconfig, and setconfig.
• Use the Rust toolchain version prior to nightly-2026-04-29 to avoid errors related to lib/rustlib/src/rust/library/std/src/sys/net/connection/socket/unix.rs.

See the apps PR #3482 .

PR verification Self-Check

• My PR adheres to Contributing Guidelines and Documentation (git commit title and message, coding standard, etc).
• My PR is ready for review and can be safely merged into a codebase.

[lupyuen]

@no1wudi Could you help to review the PR thanks :-)

[lupyuen]

@toku-mac Could you check CMakeLists.txt thanks :-)

ERROR __main__.py:618: Check failed: /home/runner/work/nuttx/nuttx/nuttx/arch/sim/src/sim/CMakeLists.txt
cmake-format check failed, run following command to update the style:
  $ cmake-format <src> -o <dst>

[toku-mac]

Sorry, I fixed in commit 118d09c.

[lupyuen]

@toku-mac Remember to add "Signed-off-by" thanks :-)

[toku-mac]

I squashed at commit e14a952 :-)

[toku-mac]

@lupyuen

failing checks
    Build / msys2 (msys2) (pull_request)Cancelled after 365 minutes 

It appears the process is stuck at this point. Could you please review the details?

[lupyuen]

@simbit18 Any idea what's wrong with the Windows build? I restarted but it didn't help thanks!