Kill implicit joining of adjacent strings

[bearophile]

Stewart Gordon:

> You mean make ~ right-associative?  I think this'll break more code than 
> it fixes.
> 
> But implementing a compiler optimisation so that var ~ ctc ~ ctc is 
> processed as var ~ (ctc ~ ctc), _in those cases where they're 
> equivalent_, would be sensible.
> 
> ctc = compile-time constant
> 
> Stewart.

It may be good to add that comment here, if you want I may add it myself:
http://d.puremagic.com/issues/show_bug.cgi?id=3827

Bye,
bearophile