Generates a C++ friendly name.
Call this function to create a C++ friendly name from a name that contains characters that cannot be used by C++. An acceptable C++ name can contain upper- or lowercase letters, digits, or an underscore ("_").
This function checks the old name character by character, skipping any unusable characters. If the old name contains no friendly characters, the function returns the new name as "My". If the new friendly name begins with a digit, this function prepends the new name with "My".