Revert "[DebugInfo] Fix bug in LiveDebugVariables."

This reverts commit 8f548ff2a1819e1bc051e8218584f1a3d2cf178a.

buildbot failure in LLVM on clang-ppc64be-linux
http://lab.llvm.org:8011/builders/clang-ppc64le-linux/builds/19765

llvm-svn: 341290
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index 4c002d4..b258a0e 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -578,28 +578,23 @@
     MachineBasicBlock *MBB = &*MFI;
     for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
          MBBI != MBBE;) {
-      // Use the first debug instruction in the sequence to get a SlotIndex
-      // for following consecutive debug instructions.
-      if (!MBBI->isDebugInstr()) {
+      if (!MBBI->isDebugValue()) {
         ++MBBI;
         continue;
       }
-      // Debug instructions has no slot index. Use the previous
-      // non-debug instruction's SlotIndex as its SlotIndex.
+      // DBG_VALUE has no slot index, use the previous instruction instead.
       SlotIndex Idx =
           MBBI == MBB->begin()
               ? LIS->getMBBStartIdx(MBB)
               : LIS->getInstructionIndex(*std::prev(MBBI)).getRegSlot();
-      // Handle consecutive debug instructions with the same slot index.
+      // Handle consecutive DBG_VALUE instructions with the same slot index.
       do {
-        // Only handle DBG_VALUE in handleDebugValue(). Skip all other
-        // kinds of debug instructions.
-        if (MBBI->isDebugValue() && handleDebugValue(*MBBI, Idx)) {
+        if (handleDebugValue(*MBBI, Idx)) {
           MBBI = MBB->erase(MBBI);
           Changed = true;
         } else
           ++MBBI;
-      } while (MBBI != MBBE && MBBI->isDebugInstr());
+      } while (MBBI != MBBE && MBBI->isDebugValue());
     }
   }
   return Changed;