This means that "./sync-all commit" will record in submodules first,
and then prompt you to record a patch updating the version of the
submodules last. Should make it less likely that we forget to update
the submodules' versions.

If anyone wants to do this in the future, they should just set
appropriate CC_OPTS/LD_OPTS variables instead.

Apparently git ignores the --git-dir argument.

Based on a patch from rassilon.

It required the old build system, so didn't work.

This porting method has bitrotted; use cross-compilation now

From StephenBlackheath

This solves the problem of how to define MIN_VERSION_base for
the binary package.

Also fixed a couple of build system bugs along the way.

This removes the '.PHONY' rule, so means that "make" in a built tree
won't repeat the check.

We also now check the .cabal files for the executables as well as the
libraries.

This is needed to make things like this work:

type N = 9
myValue = fromSing (sing :: Sing N)

If we don't look trough the synonym, we get an error that `SingI N` can't
be solved.

See Note [Kind-generalise in tcRnType] in TcRnDriver, and
the notes in Trac #7688

A standard git push doesn't make sense for them

by obtaining GlobalCrossCompilePrefix from mk/config.mk and
using that to include mk/$(GlobalCrossCompilePrefix)build.mk
instead of mk/build.mk when present.

Note: GlobalCrossCompilePrefix is basically the same
      as CrossCompilePrefix, but does not depend on $(phase).

* Test: dph/modules/ExportList

Patch modified from one by Karel Gardas <karel.gardas@centrum.cz>.