1c45962273
* 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.