Implement cfi_def_cfa_register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122612 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index f5e0d20..4d7d486 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -186,6 +186,14 @@
 
 bool MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
   EnsureValidFrame();
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  MCSymbol *Label = getContext().CreateTempSymbol();
+  EmitLabel(Label);
+  MachineLocation Dest(Register);
+  MachineLocation Source(MachineLocation::VirtualFP);
+  MCCFIInstruction Instruction(Label, Dest, Source);
+  CurFrame->Instructions.push_back(Instruction);
+  return false;
   return false;
 }