* 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

llvm-svn: 1840