Fix a tcb crash and a potential bug on mainline

[Daniel Berlin]

On Oct 19, 2004, at 7:08 PM, Daniel Berlin wrote:

>
> On Oct 19, 2004, at 6:30 PM, Jeffrey A Law wrote:
>
>> On Tue, 2004-10-19 at 16:23, Daniel Berlin wrote:
>>
>>> Only if your pass performs *all* insertions and updates to statements
>>> before performing *any* removals of statements.
>> True.  However, I believe that is the case for most of our optimizers
>> right now.
>
> Except for things that just want t
Sigh.
Hit send too early by accident.

Except for things that just want to do replacements without worrying 
about what happens to the resulting statements.
Trying to keep our ir in a "minimal form" so to speak (where there are 
never dead statements) doesn't seem like the best idea, however.