avoid -Wshadow warning on GCC

When using INSTANTIATE_TEST_CASE_P with a lambda function which uses
'info' as parameter name, GCC complains that this would shadow
parameter 'info' used in the macro's VA_ARGS call.

googletest/test/gtest-param-test_test.cc

@@ -857,8 +857,8 @@ TEST_P(CustomLambdaNamingTest, CustomTestNames) {}
 INSTANTIATE_TEST_CASE_P(CustomParamNameLambda,
                         CustomLambdaNamingTest,
                         Values(std::string("LambdaName")),
-                        [](const ::testing::TestParamInfo<std::string>& info) {
+                        [](const ::testing::TestParamInfo<std::string>& tpinfo) {
-                          return info.param;
+                          return tpinfo.param;
                         });
 
 #endif  // GTEST_LANG_CXX11