Pass the -Wmissing-declarations warning.

This makes it easier to use GTest in projects that build with the
-Wmissing-declarations warning. This fixes the warning in headers and
source files, though not GTest's own tests as it is rather noisy there.

googletest/include/gtest/gtest-param-test.h

@@ -1407,21 +1407,21 @@ internal::CartesianProductHolder10<Generator1, Generator2, Generator3,
 // type testing::TestParamInfo<class ParamType>, and return std::string.
 //
 // testing::PrintToStringParamName is a builtin test suffix generator that
-// returns the value of testing::PrintToString(GetParam()). It does not work
-// for std::string or C strings.
+// returns the value of testing::PrintToString(GetParam()).
 //
 // Note: test names must be non-empty, unique, and may only contain ASCII
-// alphanumeric characters or underscore.
+// alphanumeric characters or underscore. Because PrintToString adds quotes
+// to std::string and C strings, it won't work for these types.
 
 # define INSTANTIATE_TEST_CASE_P(prefix, test_case_name, generator, ...) \
-  ::testing::internal::ParamGenerator<test_case_name::ParamType> \
+  static ::testing::internal::ParamGenerator<test_case_name::ParamType> \
       gtest_##prefix##test_case_name##_EvalGenerator_() { return generator; } \
-  ::std::string gtest_##prefix##test_case_name##_EvalGenerateName_( \
+  static ::std::string gtest_##prefix##test_case_name##_EvalGenerateName_( \
       const ::testing::TestParamInfo<test_case_name::ParamType>& info) { \
     return ::testing::internal::GetParamNameGen<test_case_name::ParamType> \
         (__VA_ARGS__)(info); \
   } \
-  int gtest_##prefix##test_case_name##_dummy_ GTEST_ATTRIBUTE_UNUSED_ = \
+  static int gtest_##prefix##test_case_name##_dummy_ GTEST_ATTRIBUTE_UNUSED_ = \
       ::testing::UnitTest::GetInstance()->parameterized_test_registry(). \
           GetTestCasePatternHolder<test_case_name>(\
               #test_case_name, \