Temporary header file '/tmp/bT4v9PzjUJ/dump1.h' with the following content will be compiled to create GCC translation unit dump:

  // add defines
  #define __STDC_VERSION__ 201710L
#define _TIME_BITS 64
#define _FILE_OFFSET_BITS 64
#define _GXX_NULLPTR_T
#define CLUTTER_ENABLE_COMPOSITOR_API 1
#define _REGEX_NELTS(n)
#define _Atomic
#define PACKED
#define getaddrinfo_a(a,b,c,d)

  // add includes
  #include "/usr/include/date/date.h"
  #include "/usr/include/date/islamic.h"
  #include "/usr/include/date/iso_week.h"
  #include "/usr/include/date/julian.h"
  #include "/usr/include/date/ptz.h"
  #include "/usr/include/date/solar_hijri.h"
  #include "/usr/include/date/tz.h"
  #include "/usr/include/date/tz_private.h"

  // add namespaces
  namespace date{typedef int tmp_add_type_1;}
  date::tmp_add_type_1 tmp_add_func_1(){return 0;};
  namespace date{namespace detail{typedef int tmp_add_type_2;}}
  date::detail::tmp_add_type_2 tmp_add_func_2(){return 0;};
  namespace date{namespace literals{typedef int tmp_add_type_3;}}
  date::literals::tmp_add_type_3 tmp_add_func_3(){return 0;};
  namespace islamic{typedef int tmp_add_type_4;}
  islamic::tmp_add_type_4 tmp_add_func_4(){return 0;};
  namespace islamic{namespace literals{typedef int tmp_add_type_5;}}
  islamic::literals::tmp_add_type_5 tmp_add_func_5(){return 0;};
  namespace julian{typedef int tmp_add_type_6;}
  julian::tmp_add_type_6 tmp_add_func_6(){return 0;};
  namespace julian{namespace literals{typedef int tmp_add_type_7;}}
  julian::literals::tmp_add_type_7 tmp_add_func_7(){return 0;};
  namespace Posix{typedef int tmp_add_type_8;}
  Posix::tmp_add_type_8 tmp_add_func_8(){return 0;};
  namespace Posix{namespace detail{typedef int tmp_add_type_9;}}
  Posix::detail::tmp_add_type_9 tmp_add_func_9(){return 0;};
  namespace date{namespace clock_cast_detail{typedef int tmp_add_type_10;}}
  date::clock_cast_detail::tmp_add_type_10 tmp_add_func_10(){return 0;};
  namespace date{namespace ctc_detail{typedef int tmp_add_type_11;}}
  date::ctc_detail::tmp_add_type_11 tmp_add_func_11(){return 0;};
  namespace iso_week{typedef int tmp_add_type_12;}
  iso_week::tmp_add_type_12 tmp_add_func_12(){return 0;};
  namespace iso_week{namespace literals{typedef int tmp_add_type_13;}}
  iso_week::literals::tmp_add_type_13 tmp_add_func_13(){return 0;};
  namespace solar_hijri{typedef int tmp_add_type_14;}
  solar_hijri::tmp_add_type_14 tmp_add_func_14(){return 0;};
  namespace solar_hijri{namespace internal{typedef int tmp_add_type_15;}}
  solar_hijri::internal::tmp_add_type_15 tmp_add_func_15(){return 0;};
  namespace solar_hijri{namespace literals{typedef int tmp_add_type_16;}}
  solar_hijri::literals::tmp_add_type_16 tmp_add_func_16(){return 0;};

  // add classes
  _G_fpos64_t* tmp_add_class_0;
  _G_fpos_t* tmp_add_class_1;
  _IO_cookie_io_functions_t* tmp_add_class_2;

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/bT4v9PzjUJ/dump1.h"