Attacking quadratic behaviors associated with SWITCH_EXPR

[Kazu Hirata]

Hi Zack,

> I concur.  In fact, I'd go farther, and suggest that we ought to be
> working with edges directly, everywhere we are currently working with
> labels, except in the parsers.

Yes.  I am thinking about starting with SWITCH_EXPR.  After that's
complete, we can probably remove GOTO_EXPR from COND_EXPR during the
lifetime of CFG.

> One might even speculate about the feasibility of constructing the
> cfg inside the parser...

Wow, I haven't thought about that far, yet. :-)

Kazu Hirata