Split Finish into Finish and FinishImpl to have a common place to do end of
file error checking. Use that to error on an unfinished cfi_startproc.

The error is not nice, but is already better than a segmentation fault.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147717 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 630a104..ca2f10e 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -255,7 +255,7 @@
   /// indicated by the hasRawTextSupport() predicate.
   virtual void EmitRawText(StringRef String);
 
-  virtual void Finish();
+  virtual void FinishImpl();
 
   /// @}
 };
@@ -1285,7 +1285,7 @@
   EmitEOL();
 }
 
-void MCAsmStreamer::Finish() {
+void MCAsmStreamer::FinishImpl() {
   // Dump out the dwarf file & directory tables and line tables.
   if (getContext().hasDwarfFiles() && !UseLoc)
     MCDwarfFileTable::Emit(this);