Teach frame lowering to ignore debug values after the terminators.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123399 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 813fad2..ad1ab28 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -162,6 +162,18 @@
   return I;
 }
 
+MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() {
+  iterator B = begin(), I = end();
+  while (I != B) {
+    --I;
+    if (I->isDebugValue())
+      continue;
+    return I;
+  }
+  // The block is all debug values.
+  return end();
+}
+
 void MachineBasicBlock::dump() const {
   print(dbgs());
 }