dtc: import latest upstream dtc

[Segher Boessenkool]

> Oh, that's strange.  I'm pretty sure I've used -x assembler when I've
> experimented with using cpp on dts manually before, and it seems to
> have worked.

Maybe you used "-x assembler-with-cpp"?  That should work better ;-)
Or just use the "-traditional-cpp" option, i.e. "gcc -E -traditional- 
cpp".

>   Note that IIRC with gcc cpp, -x assembler also means
> that # won't be handled as a cpp directive except in column 0 which is
> also an advantage for us, although no longer essential with your
> escaping support.  Not all cpps have an equivalent option, though.

This is how the traditional C pre-processor behaves.  I don't think
this is exactly what matters for DTS, or does it ever happen that
you have a # preceded only by whitespace?  The # and ## stringification
and token pasting ops will of course bite you with the ISO C pre- 
processor,
indeed.


Segher