Fix the case of a .cfi_rel_offset before any .cfi_def_cfa_offset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129362 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 3208295..92e76c9 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -221,6 +221,17 @@
   return false;
 }
 
+void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
+  EnsureValidFrame();
+  MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
+  MCSymbol *Label = getContext().CreateTempSymbol();
+  EmitLabel(Label);
+  MachineLocation Dest(Register, Offset);
+  MachineLocation Source(Register, Offset);
+  MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
+  CurFrame->Instructions.push_back(Instruction);
+}
+
 bool MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
                                     unsigned Encoding) {
   EnsureValidFrame();