Remove anonymous namespace.

Looks like the gcc in http://lab.llvm.org:8011/builders/clang-x86_64-darwin11-self-mingw32/ doesn't like "not external linkage":

/Volumes/Macintosh_HD2/buildbots/clang-x86_64-darwin11-self-mingw32/llvm.src/include/llvm/Support/YAMLTraits.h: In instantiation of 'const bool llvm::yaml::has_SequenceMethodTraits<std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> > >::value':
/Volumes/Macintosh_HD2/buildbots/clang-x86_64-darwin11-self-mingw32/llvm.src/include/llvm/Support/YAMLTraits.h:281:   instantiated from 'llvm::yaml::has_SequenceTraits<std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> > >'
/Volumes/Macintosh_HD2/buildbots/clang-x86_64-darwin11-self-mingw32/llvm.src/utils/yaml2obj/yaml2obj.cpp:627:   instantiated from here
/Volumes/Macintosh_HD2/buildbots/clang-x86_64-darwin11-self-mingw32/llvm.src/include/llvm/Support/YAMLTraits.h:243: error: 'llvm::yaml::SequenceTraits<std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> > >::size' is not a valid template argument for type 'size_t (*)(llvm::yaml::IO&, std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> >&)' because function 'static size_t llvm::yaml::SequenceTraits<std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> > >::size(llvm::yaml::IO&, std::vector<<unnamed>::COFFYAML::Relocation, std::allocator<<unnamed>::COFFYAML::Relocation> >&)' has not external linkage