* Changing C-strings to be const.
* Changed variable-length arrays to std::vector to avoid warnings. VLA is a compiler extension.
* Changed `#define` inside functions into `constexpr int` to preserve scoping and avoid macro redefinition warnings.
* Disabled warnings for modifying `CMAKE_CXX_FLAGS` caused by `check_symbol_exists`, which temporarily modifies the flag to do a compile check.
* Fixed VLA in rccl UT.
[ROCm/rccl commit: 1c45962273]
corey-derochie-amd
ad1384bea1