c: consider enabling hardening options when building C/C++

e.g. https://openssf.org/blog/2023/11/29/strengthening-the-fort-openssf-releases-compiler-options-hardening-guide-for-c-and-c/

No files, tests, or build entry points are named. Start by reviewing the linked OpenSSF C/C++ hardening guide and locating the repository’s C/C++ build configuration; determine which options are applicable and how they should be validated. Done means the selected hardening options are enabled without breaking supported builds, with validation documented by the project’s existing checks.

Written by the indexing model from the issue text.