Revert "Revert "[PDB] Extend IPDBSession's interface to retrieve frame data""

This reverts commit 466ce67d6ec444962e5cc0136243c16a453190c0.

llvm-svn: 345010
diff --git a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
index baab0a2..7807e31 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
@@ -200,6 +200,11 @@
   return nullptr;
 }
 
+std::unique_ptr<IPDBEnumFrameData>
+NativeSession::getFrameData() const {
+  return nullptr;
+}
+
 void NativeSession::initializeExeSymbol() {
   if (ExeSymbol == 0)
     ExeSymbol = Cache.createSymbol<NativeExeSymbol>();