C cannot read the overflow bit after an ADD, because of it's abstractions ... so I would say modern ASM is still lower in some aspects because it has less constrains and more importantly, it is less expressive, which is the whole idea of this hierarchy.

The compiler should offer a macro for that. Then the question is whether to take the specification or the implementation at which point it's an absurd question to begin with. You could compare -O0 binaries, bypassing the optimization question, too.

High/low is not fine grained enough. IIRC, prolog for example would be dubbed a fifth generation language, after assembler, goto hell macro compilers, structured functional programming, and DSLs. Now coq and the like seem to be of yet a higher order (pun intended, sorry).