Move pdb code into pdb namespace.

llvm-svn: 268544
diff --git a/llvm/lib/DebugInfo/PDB/PDBSymbolData.cpp b/llvm/lib/DebugInfo/PDB/PDBSymbolData.cpp
index a948c2d..62bb6f3 100644
--- a/llvm/lib/DebugInfo/PDB/PDBSymbolData.cpp
+++ b/llvm/lib/DebugInfo/PDB/PDBSymbolData.cpp
@@ -15,6 +15,7 @@
 #include <utility>
 
 using namespace llvm;
+using namespace llvm::pdb;
 
 PDBSymbolData::PDBSymbolData(const IPDBSession &PDBSession,
                              std::unique_ptr<IPDBRawSymbol> DataSymbol)