Add support for .cfi_register now that it is easy to extent the representation
to support it. Original patch with the parsing and plumbing by the PaX team and
Roman Divacky. I added the bits in MCDwarf.cpp and the test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168565 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index e53bc7b..32dee5e 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -227,6 +227,7 @@
   virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
   virtual void EmitCFISignalFrame();
   virtual void EmitCFIUndefined(int64_t Register);
+  virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
 
   virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
   virtual void EmitWin64EHEndProc();
@@ -1047,6 +1048,16 @@
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
+  MCStreamer::EmitCFIRegister(Register1, Register2);
+
+  if (!UseCFI)
+    return;
+
+  OS << "\t.cfi_register " << Register1 << ", " << Register2;
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitWin64EHStartProc(const MCSymbol *Symbol) {
   MCStreamer::EmitWin64EHStartProc(Symbol);