libsctp is currently compiled with "-Werror" flag. For GCC6 additional flag "-std=gnu++98" is required for hotspot compilation. But due to peculiarities of hotspot build flags that option needs to be specified using --with-extra-cflags configure option (--with-extra-cxxflags is ignored by hotspot). This causes incorrect (for C) "-std" value to be applied to all C code in jdk. That causes compiler warnings and libsctp breaks compilation because of Werror enabled.