* Add new method localLookup

* Add new method localLookup
* SymbolTable::remove(Value *N) checks to see if we are internally
  inconsistent before looking for a type plane (caused a crash)
* insertEntry now does a local lookup instead of a global lookup, which was
  causing an infinite loop in the renamer logic.
* Added assertions to make sure stuff stays happy
* Now the linker correctly links the SPECINT2000 mcf benchmark

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1840 91177308-0d34-0410-b5e6-96231b3b80d8