[Transforms] Use a range-based for loop (NFC)

Author: kazutakahirata

llvm/lib/Transforms/Utils/CodeExtractor.cpp

@@ -1735,13 +1735,9 @@ CodeExtractor::extractCodeRegion(const CodeExtractorAnalysisCache &CEAC,
   NumExitBlocks = ExitBlocks.size();
 
   for (BasicBlock *Block : Blocks) {
-    Instruction *TI = Block->getTerminator();
-    for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
-      if (Blocks.count(TI->getSuccessor(i)))
-        continue;
-      BasicBlock *OldTarget = TI->getSuccessor(i);
-      OldTargets.push_back(OldTarget);
-    }
+    for (BasicBlock *OldTarget : successors(Block))
+      if (!Blocks.contains(OldTarget))
+        OldTargets.push_back(OldTarget);
   }
 
   // If we have to split PHI nodes of the entry or exit blocks, do so now.