Fix use of unnamed type as template argument warnings on Clang.

- When compiling Ceres without C++11 but with glog, then the unnamed
  enum results in a compiler warning when
  google::GetReferenceableValue(.) is invoked with the unnamed enum as a
  template parameter (unnamed-type-template-args) which was not legal
  prior to C++11.

Change-Id: Iddbed05e2199865ab915f2c5817ce917bb0609b5

include/ceres/tiny_solver_cost_function_adapter.h

diff --git a/include/ceres/tiny_solver_cost_function_adapter.h b/include/ceres/tiny_solver_cost_function_adapter.h
index 2ba1a2d..d8599e4 100644
--- a/include/ceres/tiny_solver_cost_function_adapter.h
+++ b/include/ceres/tiny_solver_cost_function_adapter.h
@@ -76,7 +76,7 @@
 class TinySolverCostFunctionAdapter {
  public:
   typedef double Scalar;
-  enum {
+  enum ComponentSizeType {
     NUM_PARAMETERS = kNumParameters,
     NUM_RESIDUALS = kNumResiduals
   };