SIMPLE: A language-independent tree IR

[law@redhat.com]

  > The most important difference is that full type information
  > is still available.
Right.  And that isn't something we necessarily were going to try and 
address with the generic RTL stuff.

  > Other differences: array and structure references are not decomposed,
But I believe we can handle this in generic RTL; in fact, you and I discussed
it at length :-)

  > looping constructs are still intact,
Right.   I really don't have a strong opinion about whether or not generic
RTL needs to keep looping constructs intact.  I really haven't thought much
about it.

  > variables have not been assigned  memory slots.
This is one of the major problems with our compiler :(

Jeff