Rename PPC MTCTRse to MTCTRloop

As the pairing of this instruction form with the bdnz/bdz branches is now
enforced by the verification pass, make it clear from the name that these
are used only for counter-based loops.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182296 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/PPCCTRLoops.cpp

@@ -627,7 +627,7 @@ check_block:
   CheckPreds = true;
   for (MachineBasicBlock::iterator IE = MBB->begin();; --I) {
     unsigned Opc = I->getOpcode();
-    if (Opc == PPC::MTCTRse || Opc == PPC::MTCTR8se) {
+    if (Opc == PPC::MTCTRloop || Opc == PPC::MTCTR8loop) {
       CheckPreds = false;
       break;
     }