doc: release-notes: Add C++ library release notes
This commit adds the C++ library release notes for the Zephyr 3.3
release.
@@ -949,6 +949,16 @@ Libraries / Subsystems
standard library (e.g. Standard Template Library) can now select
:kconfig:option:`CONFIG_REQUIRES_FULL_LIBC`, which automatically selects
a compatible C++ standard library.
+ * Introduced :kconfig:option:`CONFIG_CPP_MAIN` to support defining ``main()``
+ function in a C++ source file. Enabling this option makes the Zephyr kernel
+ invoke ``int main(void)``, which is required by the ISO C++ standards, as
+ opposed to the Zephyr default ``void main(void)``.
+ * Added no-throwing implementation of new operator to the C++ minimal
+ library.
+ * Added support for new operator with alignment request (C++17) to the C++
+ minimal library.
+ * Added GNU C++ standard library support with Picolibc when using a suitably
+ configured toolchain (e.g. the upcoming Zephyr SDK 0.16.0 release).
* Cache
