add library_async.js

For kripken/emscripten-fastcomp#39

OK. I just felt it safe this way, especially using different languages at
the same time.
I will fix it.
On Jul 7, 2014 5:16 PM, "Alon Zakai" <notifications@github.com> wrote:

> In src/library_async.js:
>
> > +    emscripten_async_stack_restore__deps: ['__async_stacktop'],
> > +    emscripten_async_stack_restore__sig: 'vi',
> > +    emscripten_async_stack_restore__asm: true,
> > +    emscripten_async_stack_restore: function(top) {
> > +        top = top|0;
> > +        ___async_stacktop = top;
> > +    },
> > +
> > +    emscripten_async_stack_alloc__deps: ['__async_stacktop'],
> > +    emscripten_async_stack_alloc__sig: 'ii',
> > +    emscripten_async_stack_alloc__asm: true,
> > +    emscripten_async_stack_alloc: function(size) {
> > +        size = size|0;
> > +        var ret = 0;
> > +        ret = ___async_stacktop;
> > +        ___async_stacktop = (___async_stacktop + size)|0;
>
> JS order of operations means you don't need the parens here.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/kripken/emscripten/pull/2482/files#r14630787>.
>