error: ‘runtime_error’ is not a member of ‘std’

[rpaasche]

Defining C4_EXCEPTIONS_ENABLED and C4_ERROR_THROWS_EXCEPTION causes the error (with c++17):

c4core/src/c4/error.cpp:115:20: error: ‘runtime_error’ is not a member of ‘std’
  115 |         throw std::runtime_error(buf);
      |   

To fix this we have to add #include <stdexcept> to error.cpp:31+

#if defined(C4_EXCEPTIONS_ENABLED) && defined(C4_ERROR_THROWS_EXCEPTION)
#   include <exception>
+ #   include <stdexcept>
#endif