I've always thought that there would be more value in exactly the opposite - a pathological C compiler (or C++ compiler, POSIX operating system, etc.). The pathological compiler would always implement undefined behavior in the most surprising, unpredictable manner - e.g., uninitialized memory would have a properly randomized value that changes from one run to the next, overflows would result in random values, etc.
That way, any programs that are made to work on the pathological implementation are largely guaranteed to rely only on standardized behavior, and work on any other standards compliant implementation.
That way, any programs that are made to work on the pathological implementation are largely guaranteed to rely only on standardized behavior, and work on any other standards compliant implementation.