sys/cpp11-compat: use new/delete operators from sys/cpp_new_delete

[gschorcht]

Contribution description

This PR provides code deduplication as well as the ability for an application to use (re)defined new/delete operators without requiring libstdc++.

1. The sys/cpp11-compat module (re)defines the new/delete operators but depends on libstdc++ even for new/delete operators that don't need libtsdc++. Module sys/cpp_new_delete provides these operators for platforms that don't have the libstdc++. Since these operators in sys/cpp11-compat are just wrappers for standard malloc/free functions like in sys/cpp_new_delete, the new/delete operators that don't need libstdc++ are used from sys/cpp_new_delete. Only the new/delete operators that require the libstd++ are left in sys/cpp11-compat.

   So it is sufficient for the use of the (re)defined new/delete operators that an application uses the module sys/cpp_new_delete instead of sys/cpp11-compat and thus also works on platforms without libstdc++.

2. On ARM platforms, __dso_handle is used for dynamic shared objects. But it is also required if global static objects are used. To avoid that sys/cpp11_compat is required only for using the (re)defined new/delete operators, __dso_handle is moved to module sys/cpp_new_delete

Testing procedure

Green CI.

Issues/PRs references

Uses the module introduced by PR #17464

[gschorcht]

Thanks for reviewing and merging.

[jenswet]

Hi @gschorcht,

Trying to understand the cpp11-compat and cpp_new_delete structure I have a question regarding this PR:
The docs of cpp_new_delete state the following:

@brief      This module provides the `new` and `delete` operators for platforms
            that do not use `libstdc++`.
@warning    This module is automatically selected, if needed. Never add it
            manually.

# Background

On some platforms `libstdc++` is not used or not available, like on the AVR.
Such platforms can use this module to implement the C++ `new` and `delete`
operators using `malloc` and `free` respectively. However, to be thread-safe,
a thread-safe implementation of `malloc` and `free` must be present.

# Usage

This module is intended to be use by platforms that not providing the required
operators. Hence, application developers and users should never select this
module by hand.

This PR adds the above module whenever cpp-compat is selected which contradicts to the above docs. Which is correct?
I'd like to file a PR to break down cpp11-compat in separate modules and align them better to the current RIOT structure, but first I need to understand this.

Thanks a lot!

CC @maribu