* Clean up InstrForest

* Clean up InstrForest
* Fix ins sel problem, test case:
void "foo" (int *%x, int *%y)

begin
        seteq int *%x, %y
        ret void
end

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@552 91177308-0d34-0410-b5e6-96231b3b80d8