Tweak TCPIP headers for more GCC friendliness

This is still a long way from being possible to compile with GCC. The main
aim here is to facilitate preprocessing of TCPIPLibs clients so that we can
run `cppcheck` on them.

The problem being addressed is that the GCC preprocessor always looks
preferentially for include files in the same directory as the one that
features the `#include` statement. This means that when

* `machine/limits.h` does `#include <limits.h>`
* `machine/stdarg.h` does `#include <stdarg.h>`
* `sys/signal.h` does `#include <signal.h>`
* `sys/time.h` does `#include <time.h>`

then, rather than including the top-level version of the header, as intended,
GCC ends up in an infinite loop of inclusion.

To deal with this with the minimum of side-effects, the recursive includes
are now conditional on `__GNUC__` bein undefined - except `machine/stdarg.h`
which adds nothing to `stdarg.h` (so it's recommended that where GCC
compatibility is required, it is simply changed to `#include <stdarg.h>`).

Where possible, instances of `#include <machine/limits.h>` within the
TCPIPLibs headers have been prefixed with `#include <limits.h>`, and
similarly for the others. The extra inclusion of the top-level header
should be harmless for Norcroft compilation, but ensures that clients of
those second-tier headers are less likely to need an additional `#include`
of a top-level header in order to enable `cppcheck`.
21 jobs for CrossCompilationSupportOld in 4 minutes and 49 seconds (queued for 4 seconds)
latest
Status Job ID Name Coverage
  Static Analysis
passed #23923
cross
cppcheck

00:00:11

passed #23916
cross
gitattributes

00:00:01

passed #23917
cross
gitignore

00:00:00

passed #23920
cross
head_log

00:00:01

passed #23922
cross
head_whitesp

00:00:00

passed #23918
cross
license

00:00:00

passed #23921
cross
makefile

00:00:01

passed #23919
cross
versionnum

00:00:01

 
  Softload
passed #23924
cross
softload

00:00:13

failed #23925
cross allowed to fail
softload_gnu

00:00:11

 
  Disc
failed #23926
cross allowed to fail
disc_BuildHost

00:00:14

failed #23927
cross allowed to fail
disc_Disc

00:00:26

 
  Rom
failed #23928
cross allowed to fail
rom_BCM2835

00:00:25

failed #23935
cross allowed to fail
rom_iMx6

00:00:25

failed #23929
cross allowed to fail
rom_IOMD32

00:00:24

failed #23930
cross allowed to fail
rom_OMAP3

00:00:25

failed #23931
cross allowed to fail
rom_OMAP4

00:00:26

failed #23932
cross allowed to fail
rom_OMAP5

00:00:25

failed #23933
cross allowed to fail
rom_Titanium

00:00:25

failed #23934
cross allowed to fail
rom_Tungsten

00:00:24

 
  Cleanup
passed #23936
cross
cleanup

00:00:01

 
Name Stage Failure
failed
rom_iMx6 Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_Tungsten Rom
------------------------------------------------------------------------------
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_Titanium Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS4'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_OMAP5 Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS4'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_OMAP4 Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_OMAP3 Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_IOMD32 Rom
------------------------------------------------------------------------------
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
rom_BCM2835 Rom
Batched errors...
Error running make export (hdrs) on module 'FileCore'.
Error running make export (hdrs) on module 'ADFS'.
Error running make export (hdrs) on module 'RamFS'.
Error running make export (hdrs) on module 'SCSIFS'.
Error running make export (hdrs) on module 'SDFS'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
disc_Disc Disc
Error running make export (hdrs) on module 'PDumperE2'.
Error running make export (hdrs) on module 'PDumperIW'.
Error running make export (hdrs) on module 'PDumperLJ'.
Error running make export (hdrs) on module 'DesktopBoot'.
Error running make export (hdrs) on module 'PatchesPatch'.
Error running make export (hdrs) on module 'ChangeFSI'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
disc_BuildHost Disc
Error running make export (hdrs) on module 'egrep'.
Error running make export (hdrs) on module 'grep'.
Error running make export (hdrs) on module 'mkdir'.
Error running make export (hdrs) on module 'sed'.
Error running make export (hdrs) on module 'wc'.
Error running make export (hdrs) on module 'ShrinkWrap'.
------------------------------------------------------------------------------
Cleaning up file based variables
ERROR: Job failed: exit status 1
failed
softload_gnu Softload
mkdir -p /home/gitlab-runner/builds/hYz1sbzj/0/bavison/TCPIPLibs/RiscOS/Install/TCPIPLibs
cp -afL inetlib.h /home/gitlab-runner/builds/hYz1sbzj/0/bavison/TCPIPLibs/RiscOS/Install/TCPIPLibs/inetlib.h
[ ! -f ../VersionNum ] || cp -afL ../VersionNum /home/gitlab-runner/builds/hYz1sbzj/0/bavison/TCPIPLibs/RiscOS/Install/TCPIPLibs/LibVersion
inetlib: header export complete
make[1]: Target 'install' not remade because of errors.
CLibrary:136: recipe for target 'install' failed
make: *** [install] Error 2
Cleaning up file based variables
ERROR: Job failed: exit status 1