Revert "[codeview] Make obj2yaml/yaml2obj support .debug$S..."

This is causing failures on linux bots with an invalid stream
read.  It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.

llvm-svn: 305371
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
index 81a9d3e..396dffa 100644
--- a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
@@ -177,7 +177,7 @@
 }
 
 void DbiModuleDescriptorBuilder::addDebugSubsection(
-    std::shared_ptr<DebugSubsection> Subsection) {
+    std::unique_ptr<DebugSubsection> Subsection) {
   assert(Subsection);
   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
       std::move(Subsection), CodeViewContainer::Pdb));
diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBStringTableBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBStringTableBuilder.cpp
index 90acfad..a472181 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBStringTableBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBStringTableBuilder.cpp
@@ -52,11 +52,6 @@
   return Size;
 }
 
-void PDBStringTableBuilder::setStrings(
-    const codeview::DebugStringTableSubsection &Strings) {
-  this->Strings = Strings;
-}
-
 Error PDBStringTableBuilder::writeHeader(BinaryStreamWriter &Writer) const {
   // Write a header
   PDBStringTableHeader H;