libstdc++: Relocate c++config.h from include/ to libstdc++ to preserv…

[cuiziweizw]

…e upstream integrity

Summary

• Add c++config.h to improve libstdc++ configuration support
• Update CMakeLists.txt and libsupc++.defs to integrate the new config header
• Remove the obsolete 0001-libsupc-Add-missing-header-files.patch to clean up the codebase

These changes enhance the maintainability and portability of the C++ standard library and simplify the build process.

Impact

• c++config.h is a configuration file that supports the libstdc++ library. Due to its upstream origin, the code style within this file cannot be adjusted to meet the Apache NuttX community's CI formatting requirements. It may be necessary to skip the community CI format checks for this file to avoid unnecessary failures.

Testing

Test Environment

Host: Linux x86_64
Build config: default libstdc++ options
Board: QEMU/simulator

Test Steps

1. Clean and rebuild nuttx
2. Enable CONFOG_LIBSUPCXX and CONFIG_CXXTEST
3. Ensure successful compilation with no errors
4. Run the cxxtest example to verify libsupc++ functionality

Test Results

Simulated Test Scenario

./tools/configure.sh sim:nsh
make menuconfig
make -j16

nsh> cxxtest

[xiaoxiang781216]

@cuiziweizw please fix ci check error.

[cuiziweizw]

c++config.h is a configuration file that supports the libstdc++ library. Due to its upstream origin, the code style within this file cannot be adjusted to meet the Apache NuttX community's CI formatting requirements. It may be necessary to skip the community CI format checks for this file to avoid unnecessary failures.