Add CFIStartSections to the asm printer. Add an assert that at least
one of the sections is created.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131124 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index c7fc190..603ae83 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -193,6 +193,7 @@
                                      unsigned Isa, unsigned Discriminator,
                                      StringRef FileName);
 
+  virtual void EmitCFISections(bool EH, bool Debug);
   virtual void EmitCFIStartProc();
   virtual void EmitCFIEndProc();
   virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
@@ -764,6 +765,24 @@
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitCFISections(bool EH, bool Debug) {
+  MCStreamer::EmitCFISections(EH, Debug);
+
+  if (!UseCFI)
+    return;
+
+  OS << "\t.cfi_sections ";
+  if (EH) {
+    OS << ".eh_frame";
+    if (Debug)
+      OS << ", .debug_frame";
+  } else if (Debug) {
+    OS << ".debug_frame";
+  }
+
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitCFIStartProc() {
   MCStreamer::EmitCFIStartProc();