Not so much "obfuscated C" as it is "embedding a binary into a C program". You can still do something similar with modern compilers:

    char code[] = { /* put your bytes here */ };
    ((void(*)())code)();

I believe it is technically UB, but it does exactly what you'd think it does, and if compilers started doing funny things with it, you wouldn't be able to write things like JITs at all. A tiny demonstration of this can be found at the bottom of C4x86: https://github.com/EarlGray/c4/blob/master/c4x86.c