[LLVMdev] RFC: implicit null checks in llvm

[Sanjoy Das]

> One thing to note: it is usually impractical for managed languages to
> use implicit null pointer exceptions unless they have some way to
> "heal" the implicit null check sites into explicit null checks as they
> fail.  Unless you have a way to quickly converge your program to a
> point where no implicit null checks actually fail at runtime, checking
> for null pointers via virtual memory tricks is a pessimization.
>
> This can be done via code patching / invalidation etc. as Andy
> mentioned.

^^ you can ignore these two paragraphs.  They're not incorrect, but I
realized that they're not relevant to what you were suggesting.