Patched my previous patch ($ vs $$, && vs if/then/fi). Installing a
Happy binary-dist still only creates a happy and no happy-1.6
executable, but this has very probably nothing to do with my changes.

Two checks for empty file lists added.

We have to be very careful with numeric literals in the C part, in
this case 0xff (of type int = 4 bytes on Alpha) was shifted left 56
times => always zero  :-{  Using an L or UL suffix is not always
practical, because the needed size depends on conditional typedefs
somewhere else. Solution: Cast!  :-P  ghc/includes contains some more
suspicious literals, but I did not have a look at them yet.

This commit makes a start at implementing polymorphic usage
annotations.

* The module Type has now been split into TypeRep, containing the
  representation Type(..) and other information for `friends' only,
  and Type, providing the public interface to Type.  Due to a bug in
  the interface-file slurping prior to ghc-4.04, {-# SOURCE #-}
  dependencies must unfortunately still refer to TypeRep even though
  they are not friends.

* Unfoldings in interface files now print as __U instead of __u.
  UpdateInfo now prints as __UA instead of __U.

* A new sort of variables, UVar, in their own namespace, uvName, has
  been introduced for usage variables.

* Usage binders __fuall uv have been introduced.  Usage annotations
  are now __u - ty (used once), __u ! ty (used possibly many times),
  __u uv ty (used uv times), where uv is a UVar.  __o and __m have
  gone.  All this still lives only in a TyNote, *for now* (but not for
  much longer).

* Variance calculation for TyCons has moved from
  typecheck/TcTyClsDecls to types/Variance.

* Usage annotation and inference are now done together in a single
  pass.  Provision has been made for inferring polymorphic usage
  annotations (with __fuall) but this has not yet been implemented.
  Watch this space!

No more RAWCPP, thank you.

Use +RTS -S<file> rather than +RTS -s<file>, since the latter only
gives summary statistics now.

A prime example of how an inconsistent .hi-boot file can really ruin
your day: the definition of CoreRules in CoreSyn.hi-boot was out of
sync with the real one, which meant that the compiler generated the
wrong code for a `seq` on something of type CoreRules.

oops, forgot to commit this yesterday.

RAWCPP is now '$(CPP) -undef -traditional'.

[Simon: this should fix that -funfolding-use-threshold0 lint bug]

[Kevin: have a look at WwLib.mkWwBodies.  Isn't it a thing of beauty?
	Could you think about whether the CPR stuff could be cleaned
	up a bit?  The strictness stuff is much shorter.]


This commit tidies up WwLib.mkWwBodies, fixing a couple of bugs.

* One bug showed up when CPR made a worker return an unboxed tuple,
  but the worker didn't have any other arguments.  The "add a void arg"
  hack needed to be generalised a bit.

* The other bug showed up when booting the compiler.  There's a long
  comment near splitProductType in WwLib.lhs that explains the problem.

Enlarged heap for 2.10-compiled Happy on Alphas

pre-4.03 didn't have __HASKELL98__, use something else.

Main things:

* Add splitProductType_maybe to DataCon.lhs, with type
  splitProductType_maybe
	:: Type 			-- A product type, perhaps
	-> Maybe (TyCon, 		-- The type constructor
		  [Type],		-- Type args of the tycon
		  DataCon,		-- The data constructor
		  [Type])		-- Its *representation* arg types

  Then use it in many places (e.g. worker-wrapper places) instead
  of a pile of junk

* Clean up various uses of dataConArgTys, which were plain wrong because
  they weren't passed the existential type arguments.  Most of these calls
  are eliminated by using splitProductType_maybe above.  I hope I correctly
  squashed the others. This fixes a bug that Meurig's programs showed up.

    module FailGHC (killSustainer) where
    import Weak
    import IOExts

    data Sustainer = forall a . Sustainer (IORef (Maybe a)) (IO ())

    killSustainer :: Sustainer -> IO ()
    killSustainer (Sustainer _ act) = act

  The above program used to kill the compiler.

* A fairly concerted attack on the Dreaded Space Leak.
	- Add Type.seqType, CoreSyn.seqExpr, CoreSyn.seqRules

	- Add some seq'ing when building Ids and IdInfos
		These reduce the space usage a lot

	- Add CoreSyn.coreBindsSize, which is pretty strict in the program,
		and call it when we have -dshow-passes.

	- Do not put the inlining in an Id that is being plugged into
		the result-expression of the simplifier.  This cures
		a the 'wedge' in the space profile for reasons I don't understand fully

  Together, these things reduce the max space usage when compiling PrelNum from
  17M to about 7Mbytes.

  I think there are now *too many* seqs, and they waste work, but I don't have
  time to find which ones.

  Furthermore, we aren't done. For some reason, some of the stuff allocated by
  the simplifier makes it through all during code generation and I don't see why.
  There's a should-be-unnecessary call to coreBindsSize in Main.main which
  zaps some, but not all of this space.

  -dshow-passes reduces space usage a bit, but I don't think it should really.

  All the measurements were made on a compiler compiled with profiling by
  GHC 3.03.    I hope they carry over to other builds!

* One trivial thing: changed all variables 'label' to 'lbl', becuase the
  former is a keyword with -fglagow-exts in GHC 3.03 (which I was compiling with).
  Something similar in StringBuffer.

- Add findPtr() - searches through the heap for an occurrence of a
  given value.  Useful when debugging.

Workaround bug in Linux's glibc 2.1:  don't fflush(stdout) before
writing to stderr.

use shutdownHaskellAndExit().

- add USE_REPORT_PRELUDE
- Directory and Time don't need -monly-3-regs any more
- remove a -fno-prune-tydecls

Changed vars of the form _unused to zz_unused, since 3.02 doesn't understand
this convention.

Don't attempt to discover the exact location of cpp, instead use 'gcc
-E'.  With the right combination of flags, it seems we can get the
same behaviour as calling cpp directly.

Update to match CgUsages.hi-boot-5

Recover the -funbox-strict-fields test.

4.04

4.04 changes.

- add 4.04 release notes
- several other docfixes and markup fixes.

link in NonTermination_static_closure.

add NonTermination_closure.

Fix my email address.

Small typos from Wolfram Kahl.

USE_REPORT_PRELUDE patches from Wolfram Kahl.

Add NonTermination to the exception type.  Prints as "<<loop>>"
(better suggestions welcome).

Keep the original name for non-exported record selectors and class
methods.

Cygwin B19 compatibility fixes

foreign export regression test

A 'foreign export' (static) declaration doesn't bind a name but
simply adds an occurrence of a name.

Fix shadowing bug in rule matcher (showed up in spectral/rewrite)

Back out rev 1.30 - it broke a lot of things.

Reduce ScrutConDiscount from 3 to 2.

- charge 1 for a case expression

- give a discount of opt_UF_ScrutConDiscount each time a constructor
  is scrutinised

(previously a case expression was not charged for at all, and the
discount for a scrutinised constructor was (opt_UF_ScrutConDiscount *
tyconFamilySize).  In 4.02, a case expression was also charged
tyconFamilySize to balance the discount, but this had the disadvantage
of charging for alternatives which may not be present in the actual
case expression).

Back out yesterday's change - needs more thought.

All Simon's recent tuning changes.  Rough summary follows:

* Fix Kevin Atkinson's cant-find-instance bug.  Turns out that Rename.slurpSourceRefs
  needs to repeatedly call getImportedInstDecls, and then go back to slurping
  source-refs.  Comments with Rename.slurpSourceRefs.

* Add a case to Simplify.mkDupableAlt for the quite-common case where there's
  a very simple alternative, in which case there's no point in creating a
  join-point binding.

* Fix CoreUtils.exprOkForSpeculation so that it returns True of (==# a# b#).
  This lack meant that
	case ==# a# b# of { True -> x; False -> x }
  was not simplifying

* Make float-out dump bindings at the top of a function argument, as
  at the top of a let(rec) rhs.  See notes with FloatOut.floatRhs

* Make the ArgOf case of mkDupableAlt generate a OneShot lambda.
  This gave a noticeable boost to spectral/boyer2


* Reduce the number of coerces, using worker/wrapper stuff.
  The main idea is in WwLib.mkWWcoerce.  The gloss is that we must do
  the w/w split even for small non-recursive things.  See notes with
  WorkWrap.tryWw.

* This further complicated getWorkerId, so I finally bit the bullet and
  make the workerInfo field of the IdInfo work properly, including
  under substitutions.  Death to getWorkerId.  Kevin Glynn will be happy.

* Make all lambdas over realWorldStatePrimTy
  into one-shot lambdas.  This is a GROSS HACK.

* Also make the occurrence analyser aware of one-shot lambdas.

* Make various Prelude things into INLINE, so that foldr doesn't
  get inlined in their body, so that the caller gets the benefit
  of fusion.  Notably in PrelArr.lhs.

Assembler/Disassembler: handle and print calls to compiled code
Evaluator: return to scheduler when entering unknown closure
StgCRun: debugging trace in miniinterpreter (temporary)
Updates: fix normal and vectored returns to Hugs