Fixes GCC 4.6 warnings (patch by Jeffrey Yasskin).

include/gtest/internal/gtest-internal.h

@@ -919,6 +919,13 @@ typedef char IsNotContainer;
 template <class C>
 IsNotContainer IsContainerTest(...) { return '\0'; }
 
+// EnableIf<condition>::type is void when 'Cond' is true, and
+// undefined when 'Cond' is false.  To use SFINAE to make a function
+// overload only apply when a particular expression is true, add
+// "typename EnableIf<expression>::type* = 0" as the last parameter.
+template<bool> struct EnableIf;
+template<> struct EnableIf<true> { typedef void type; };  // NOLINT
+
 // Utilities for native arrays.
 
 // ArrayEq() compares two k-dimensional native arrays using the
@@ -1182,7 +1189,7 @@ class GTEST_TEST_CLASS_NAME_(test_case_name, test_name) : public parent_class {\
   GTEST_TEST_CLASS_NAME_(test_case_name, test_name)() {}\
  private:\
   virtual void TestBody();\
-  static ::testing::TestInfo* const test_info_;\
+  static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;\
   GTEST_DISALLOW_COPY_AND_ASSIGN_(\
       GTEST_TEST_CLASS_NAME_(test_case_name, test_name));\
 };\