It seems libcxx needs C++20 from 12.0.0 to 17.0.6: 3b625060fc
But we're setting CMAKE_CXX_STANDARD to 17, errors on my side:
nuttx/libs/libxx/libcxx/src/include/to_chars_floating_point.h:122:46: error: ‘bit_cast’ is not a member of ‘std’
122 | const _Uint_type _Uint_value = _VSTD::bit_cast<_Uint_type>(_Value);
| ^~~~~~~~
nuttx/libs/libxx/libcxx/src/memory_resource_init_helper.h:2:8: error: ‘constinit’ does not name a type
2 | static constinit ResourceInitHelper res_init _LIBCPP_INIT_PRIORITY_MAX;
| ^~~~~~~~~
nuttx/libs/libxx/libcxx/src/memory_resource_init_helper.h:2:8: note: C++20 ‘constinit’ only available with ‘-std=c++20’ or ‘-std=gnu++20’
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>