If you wrote a C compiler that had special optimizations for a subset of C without pointers, then it would still be a C compiler, and the subset that it optimized for would still be C. (In fact, this is exactly the approach taken with languages like GLSL 1.0, although they added some extensions to make it not C anymore.)
I didn't say the Javascript implementations weren't Javascript implementations. Further, you are incorrect. A subset of C cannot be C. Are you dumb? If I make an expression language is this C because C has a little expression language inside it? It is a subset - and also a SUBSET OF AN INFINITE SET OF OTHER LANGUAGES. Hopefully you can understand my anger that baboons are apparently allowed to implement programming languages. They got it wrong with Javascript and did a complete about-turn with emscripten etc in REACTION to competitors. I look forward to laughing at your continued attempts to hide this embarrassing little abortion.
> the subset that it optimized for would still be C
This doesn't mean to imply the subset is the entirety of C; it means the subset is part of the definition of C — just like you can say "'int x = 4;' is C", even though it's a (demonstration of a) subset of C.
The JavaScript which happens to be optimised under the name "asm.js" is still JavaScript that executes in any non-optimising runtime, and the semantics with those optimisations and without are the same.
Javascript was the wrong design choice, and the asm.js people are very sensitive about this. Which is why they pretend it's "just Javascript". Nobody denies that it's backward compatible. But it is a new language, the rest is word games.
