Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

llvm-svn: 213562
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 0e85181..d3648e2 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2718,8 +2718,8 @@
       if (UserParent != BB) {
         bool UserIsSuccessor = false;
         // See if the user is one of our successors.
-        for (BasicBlock *Succ : successors(BB))
-          if (Succ == UserParent) {
+        for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
+          if (*SI == UserParent) {
             UserIsSuccessor = true;
             break;
           }