This fixes a problem where darcs tries to update it while perl has it
open. On Windows this fails. Spotted by Claus Reinke.

GHC needs package.conf and things like unlit to be in the same place

Some things were using the base3 compat library.

The packages file has an extra component (for "darcs" or "git") so we need
to take that into account when grepping.

We were looking for executable things, but not requiring that they were
files. So we were adding lots of directories (and thus their contents)
to the bindists, massively inflating their size.

We now need to make sure that they have been toException'd.
Also, the RTS doesn't know about the Deadlock exception any more.

If
    GhcWithNativeCodeGen = NO
then we don't build the NCG modules, and we define OMIT_NATIVE_CODEGEN

Otherwise it can't work out how to make in ghc/ any more.

We now set Validating=YES in mk/are-validating.mk rather than on the
commandline. This means that if you build a tree with validate then
just running make in it will use the validate flags.
"make distclean" removes mk/are-validating.mk, putting us back in
standard build mode.

We only call register if we actually have a library to be registered

Now that we don't include any header files in .hc apart from our own,
the cc-options from packages are at best superfluous, so don't pass
them.

We still pass them to .c compilations, although I've just made changes
to Cabal so that cc-options from a .cabal file are not copied into the
InstalledPackageInfo.  Most uses of cc-options in Cabal are clearly
intended to be local to the package, but they were being propagated
everywhere, almost certainly unintentionally.

The way is left open for Cabal to allow packages to specify cc-options
that get propagated in the future, if we find a use case for this.

Some old experimental change leaked in with the parallel GC patches,
it seems