Merge pull request #3055 from chrisn-arm/3.3.x

Fix compilation on alpine 3.5

src/google/protobuf/compiler/mock_code_generator.cc

@@ -55,6 +55,13 @@
 #include <google/protobuf/stubs/substitute.h>
 #include <gtest/gtest.h>
 
+#ifdef major		
+#undef major		
+#endif		
+#ifdef minor		
+#undef minor		
+#endif		
+
 namespace google {
 namespace protobuf {
 namespace compiler {