Move `/includes` to `/rts/include`, sort per package better

In order to make the packages in this repo "reinstallable", we need to
associate source code with a specific packages. Having a top level
`/includes` dir that mixes concerns (which packages' includes?) gets in
the way of this.

To start, I have moved everything to `rts/`, which is mostly correct.
There are a few things however that really don't belong in the rts (like
the generated constants haskell type, `CodeGen.Platform.h`). Those
needed to be manually adjusted.

Things of note:

 - No symlinking for sake of windows, so we hard-link at configure time.

 - `CodeGen.Platform.h` no longer as `.hs` extension (in addition to
   being moved to `compiler/`) so as not to confuse anyone, since it is
   next to Haskell files.

 - Blanket `-Iincludes` is gone in both build systems, include paths now
   more strictly respect per-package dependencies.

 - `deriveConstants` has been taught to not require a `--target-os` flag
   when generating the platform-agnostic Haskell type. Make takes
   advantage of this, but Hadrian has yet to.

1 files changed, 0 insertions, 16 deletions

diff --git a/includes/rts/Utils.h b/includes/rts/Utils.h
deleted file mode 100644
index 4aee9c3a67..0000000000
--- a/includes/rts/Utils.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/* -----------------------------------------------------------------------------
- *
- * (c) The GHC Team, 1998-2009
- *
- * RTS external APIs.  This file declares everything that the GHC RTS
- * exposes externally.
- *
- * To understand the structure of the RTS headers, see the wiki:
- *   https://gitlab.haskell.org/ghc/ghc/wikis/commentary/source-tree/includes
- *
- * ---------------------------------------------------------------------------*/
-
-#pragma once
-
-/* Alternate to raise(3) for threaded rts, for BSD-based OSes */
-int genericRaise(int sig);