cleanup: scc_iterator consumers should use isAtEnd

No functional change.  Updated loops from:

    for (I = scc_begin(), E = scc_end(); I != E; ++I)

to:

    for (I = scc_begin(); !I.isAtEnd(); ++I)

for teh win.

llvm-svn: 200789
diff --git a/llvm/lib/Target/R600/AMDILCFGStructurizer.cpp b/llvm/lib/Target/R600/AMDILCFGStructurizer.cpp
index 69ced3c..90d541e 100644
--- a/llvm/lib/Target/R600/AMDILCFGStructurizer.cpp
+++ b/llvm/lib/Target/R600/AMDILCFGStructurizer.cpp
@@ -934,8 +934,8 @@
 void AMDGPUCFGStructurizer::orderBlocks(MachineFunction *MF) {
   int SccNum = 0;
   MachineBasicBlock *MBB;
-  for (scc_iterator<MachineFunction *> It = scc_begin(MF), E = scc_end(MF);
-      It != E; ++It, ++SccNum) {
+  for (scc_iterator<MachineFunction *> It = scc_begin(MF); !It.isAtEnd();
+       ++It, ++SccNum) {
     std::vector<MachineBasicBlock *> &SccNext = *It;
     for (std::vector<MachineBasicBlock *>::const_iterator
          blockIter = SccNext.begin(), blockEnd = SccNext.end();