Merge 4f3439a804d1ac9b15dea7c0953e4b0e74e7140d into a721f1b20c605f635413e22d8b7427a8b4f3956c

Clang's -Wmissing-variable-declarations flags this as an issue since the
flag is only used in `gtest.cc`. Declare the flag beforehand to ensure
that the variable scope is properly limited to `gtest.cc`.

Signed-off-by: Enji Cooper <yaneurabeya@gmail.com>

googletest/src/gtest.cc

@@ -264,6 +264,7 @@ GTEST_DEFINE_bool_(
                                         testing::GetDefaultFailFast()),
     "True if and only if a test failure should stop further test execution.");
 
+GTEST_DECLARE_bool_(fail_if_no_test_linked);
 GTEST_DEFINE_bool_(
     fail_if_no_test_linked,
     testing::internal::BoolFromGTestEnv("fail_if_no_test_linked", false),