Compile error on Mac/Clang: missing include

[henrixapp]

Hi,

Following build error occurs, when building on Mac with llvm 15:

KaGen/kagen/context.cpp:404:24: error: implicit instantiation of undefined template 'std::basic_istringstream<char>'
    std::istringstream toker(options);
                       ^
/opt/homebrew/opt/llvm/bin/../include/c++/v1/iosfwd:140:32: note: template is declared here
    class _LIBCPP_TEMPLATE_VIS basic_istringstream;

This can be fixed by #include <sstream> in kagen/context.cpp.

[DanielSeemaier]

Thanks!