Making alloca more safe

[Frank Benoit]

dsimcha schrieb:
> Yes, but it stops the program in such a way that it's very hard to figure out
> why/where it died.  The solution, which I've wanted for a while and I think others
> have proposed, is for DMD to implicitly assert that every pointer is non-null
> before dereferencing it when in debug mode.

This would be great. The compiler could also optimize those away in
cases of repeated access without ref assign in between

void foo( Object o){
  o.toString(); // o !is null checked
  o.toHash();   // o !is null not checked, because already done
}