Fix flawfinder issue - potential buffer overflow

[eljonny]

include/internal/TestCPPUtil.h:107:33:  [2] (buffer) char:
  Statically-sized arrays can be improperly restricted, leading to potential
  overflows or other issues (CWE-119!/CWE-120). Perform bounds checking, use
  functions that limit length, or ensure that the size is larger than the
  maximum possible length.
            alignas(T) unsigned char data[sizeof(T)];

[eljonny]

I think this is a false positive but I really need to make sure.

[eljonny]

This is defined as part of the implementation of an alternative to [[clang::no_destroy]] and the operations on the data (each instance holds a std::unique_ptr object) are controlled and converted to the proper type, and those types then control how the "data" object is used and accessed, it is not an array that is indexed (even though it technically could be used like that, but it is not used that way, is not intended to be used that way, and should not in the future be used that way; it should not be because it is an internal data member).
That implementation is defined here which is where I pulled it from, where I decided the tradeoffs are appropriate for the situation.
This is absolutely a false positive.