Move pdb code into pdb namespace.

llvm-svn: 268544
diff --git a/llvm/tools/llvm-pdbdump/CompilandDumper.cpp b/llvm/tools/llvm-pdbdump/CompilandDumper.cpp
index 86b5458..b7de0f2 100644
--- a/llvm/tools/llvm-pdbdump/CompilandDumper.cpp
+++ b/llvm/tools/llvm-pdbdump/CompilandDumper.cpp
@@ -35,6 +35,7 @@
 #include <utility>
 
 using namespace llvm;
+using namespace llvm::pdb;
 
 CompilandDumper::CompilandDumper(LinePrinter &P)
     : PDBSymDumper(true), Printer(P) {}