Fixes a user reported test break (modifying a dict while iterating).

include/gtest/internal/gtest-port.h

@@ -678,6 +678,13 @@
 # define GTEST_NO_INLINE_
 #endif
 
+// _LIBCPP_VERSION is defined by the libc++ library from the LLVM project.
+#if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION)
+# define GTEST_HAS_CXXABI_H_ 1
+#else
+# define GTEST_HAS_CXXABI_H_ 0
+#endif
+
 namespace testing {
 
 class Message;