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

  // add defines
  #define __STDC_VERSION__ 201710L
#define _FILE_OFFSET_BITS 64
#define _GXX_NULLPTR_T
#define CLUTTER_ENABLE_COMPOSITOR_API 1
#define _REGEX_NELTS(n)
#define _Atomic
#define PACKED
#ifdef __cplusplus
// C17 compat layer
#define _Alignof(type) alignof(type)
#endif
#define getaddrinfo_a(a,b,c,d)

  // add includes
  #include "/usr/include/msgpack/fbuffer.h"
  #include "/usr/include/msgpack/object.h"
  #include "/usr/include/msgpack/pack.h"
  #include "/usr/include/msgpack/pack_define.h"
  #include "/usr/include/msgpack/sbuffer.h"
  #include "/usr/include/msgpack/sysdep.h"
  #include "/usr/include/msgpack/timestamp.h"
  #include "/usr/include/msgpack/unpack.h"
  #include "/usr/include/msgpack/unpack_define.h"
  #include "/usr/include/msgpack/util.h"
  #include "/usr/include/msgpack/version.h"
  #include "/usr/include/msgpack/version_master.h"
  #include "/usr/include/msgpack/vrefbuffer.h"
  #include "/usr/include/msgpack/zbuffer.h"
  #include "/usr/include/msgpack/zone.h"
  #include "/usr/include/msgpack.h"

  // 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;
  cmsghdr* tmp_add_class_3;
  group_filter* tmp_add_class_4;
  group_req* tmp_add_class_5;
  group_source_req* tmp_add_class_6;
  gzFile_s* tmp_add_class_7;
  gz_header_s* tmp_add_class_8;
  in6_addr* tmp_add_class_9;
  in6_pktinfo* tmp_add_class_10;
  in_addr* tmp_add_class_11;
  in_pktinfo* tmp_add_class_12;
  iovec* tmp_add_class_13;
  ip6_mtuinfo* tmp_add_class_14;
  ip_mreq* tmp_add_class_15;
  ip_mreq_source* tmp_add_class_16;
  ip_mreqn* tmp_add_class_17;
  ip_msfilter* tmp_add_class_18;
  ip_opts* tmp_add_class_19;
  ipv6_mreq* tmp_add_class_20;
  linger* tmp_add_class_21;
  mmsghdr* tmp_add_class_22;
  msghdr* tmp_add_class_23;
  msgpack_object* tmp_add_class_24;
  msgpack_object_kv* tmp_add_class_25;
  msgpack_packer* tmp_add_class_26;
  msgpack_sbuffer* tmp_add_class_27;
  msgpack_timestamp* tmp_add_class_28;
  msgpack_unpacked* tmp_add_class_29;
  msgpack_unpacker* tmp_add_class_30;
  msgpack_vrefbuffer* tmp_add_class_31;
  msgpack_vrefbuffer_inner_buffer* tmp_add_class_32;
  msgpack_zbuffer* tmp_add_class_33;
  msgpack_zone* tmp_add_class_34;
  msgpack_zone_chunk_list* tmp_add_class_35;
  msgpack_zone_finalizer* tmp_add_class_36;
  msgpack_zone_finalizer_array* tmp_add_class_37;
  osockaddr* tmp_add_class_38;
  sockaddr* tmp_add_class_39;
  sockaddr_in* tmp_add_class_40;
  sockaddr_in6* tmp_add_class_41;
  sockaddr_storage* tmp_add_class_42;
  ucred* tmp_add_class_43;
  z_stream_s* tmp_add_class_44;

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/gPzLfkwgrp/dump1.h"  -I/usr/include/msgpack/predef/other -I/usr/include/msgpack/predef/os