dosbox: FTBFS on aarch64-darwin

[OPNA2608]

Steps To Reproduce

Steps to reproduce the behavior:

1. build dosbox on aarch64-darwin

Build log

https://hydra.nixos.org/build/190016824/log

Additional context

Build stopped working some time between 2022-07-02 and 2022-09-10 (the above). Notable changes in the build output:

[autoreconfHook is executed]
[SDL_compat instead of real SDL]
[alot of type sizes are detected as 0:]
checking size of unsigned char... 0
checking size of unsigned short... 0
checking size of unsigned int... 0
checking size of unsigned long... 0
checking size of unsigned long long... 0
...
[SDL_net not correctly detected anymore:]
checking for SDL_net.h... no
checking for SDLNet_Init in -lSDL_net... yes
configure: WARNING: Can't find SDL_net, internal modem and ipx disabled
...
[SDL_sound not correctly detected anymore:]
checking for SDL_sound.h... no
checking for Sound_Init in -lSDL_sound... yes
checking for Sound_Seek in -lSDL_sound... yes
configure: WARNING: Can't find libSDL_sound, libSDL_sound support disabled
...
[borked:]
clang++ -DHAVE_CONFIG_H -I. -I../..  -I../../include -I/nix/store/sf8pqf0d4zp474xwi5qd2ckvym2jrfrp-SDL_compat-1.2.52/include/SDL -D_THREAD_SAFE  -g -O2 -mno-ms-bitfields  -c -o callback.o callback.cpp
In file included from callback.cpp:24:
In file included from ../../include/dosbox.h:24:
../../config.h:275:4: error: "sizeof (unsigned char) != 1"
#  error "sizeof (unsigned char) != 1"
   ^
../../config.h:282:4: error: "sizeof (unsigned short) != 2"
#  error "sizeof (unsigned short) != 2"
   ^
../../config.h:295:4: error: "can't find sizeof(type) of 4 bytes!"
#  error "can't find sizeof(type) of 4 bytes!"
   ^
../../config.h:305:4: error: "can't find data type of 8 bytes"
#  error "can't find data type of 8 bytes"
   ^
../../config.h:312:11: error: unknown type name 'Bit64u'
  typedef Bit64u Bitu;
          ^
../../config.h:313:11: error: unknown type name 'Bit64s'
  typedef Bit64s Bits;
          ^
[many more errors follow]

I sadly lack the hardware to do any testing on this, just noticed it while trying to let CI test a new platform support of something that depends on this: #203943 (comment)

Notify maintainers

@matthewbauer (maintainer of dosbox)
@peterhoeg (merged last change to dosbox, can't see an ofborg run on aarch64-darwin in the checks)

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

Whatever Hydra is using.