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

Author: kazutakahirata

llvm/lib/Transforms/IPO/SampleProfileProbe.cpp

@@ -186,9 +186,7 @@ void SampleProfileProber::computeCFGHash() {
   std::vector<uint8_t> Indexes;
   JamCRC JC;
   for (auto &BB : *F) {
-    auto *TI = BB.getTerminator();
-    for (unsigned I = 0, E = TI->getNumSuccessors(); I != E; ++I) {
-      auto *Succ = TI->getSuccessor(I);
+    for (BasicBlock *Succ : successors(&BB)) {
       auto Index = getBlockId(Succ);
       for (int J = 0; J < 4; J++)
         Indexes.push_back((uint8_t)(Index >> (J * 8)));