integer2Int#, take 3

integer2Int# again: don't flip sign unless outside [minInt,maxInt]

integer2Int# isn't sign preserving any longer, but modulo maxBound

Remove declaration of PrelBase_Bool_closure_tbl.

dataToTag# support.

Improvements to the threading model.

   - asynchronous exceptions supported.

	- killThread# can now raise an exception in the specified
	  thread.  It's new type is

		killThread# :: ThreadId# -> Exception -> IO ()

	  High-level versions:

		killThread :: ThreadId -> IO ()
		raiseInThread :: ThreadId -> Exception -> IO ()

	  (killThread raises a 'ThreadKilled' exception in the
	   specified thread).

	  If the thread has no exception handler, it is killed
	  as before.  Otherwise, the exception is passed to
	  the innermost CATCH_FRAME and the thread is woken up
	  if it was blocked.  The current computation is
	  suspended, instead of being replaced by the exception
	  (as is the case with throw).

	  Sending an exception to the current thread works too.

   - new primitive: myThreadId# :: IO ThreadId# and corresponding
     high-level version myThreadId :: IO ThreadId.

   - new primitive: yield# :: IO (), and yield :: IO ().

   - the TSO now contains a pointer to the resource currently blocked
     on (MVAR or BLACKHOLE_BQ).

  - Add a giant comment to TSO.h about what the various link fields
    are supposed to do, and invariants etc.

Support for unsafely thawing your (Byte)Arrays, i.e., added the
following ops:

 MutableArray.unsafeThawArray :: Ix ix => Array ix elt -> ST s (MutableArray s ix elt)
 MutableArray.unsafeThawByteArray :: Ix ix => ByteArray ix -> ST s (MutableByteArray s ix)
 MutableArray.thawByteArray :: Ix ix => ByteArray ix -> ST s (MutableByteArray s ix)

 ST.unsafeThawSTArray 	    :: Ix ix => Array ix elt -> ST s (STArray s ix elt)
 LazyST.unsafeThawSTArray   :: Ix ix => Array ix elt -> ST s (STArray s ix elt)

 IOExts.unsafeFreezeIOArray :: Ix ix => IOArray ix elt -> IO (Array ix elt)
 IOExts.unsafeThawIOArray   :: Ix ix => Array ix elt -> IO (IOArray ix elt)

+ removed the re-exportation of Monad that ST and LazyST did.

- misc changes to support DLLs
- StgNat* --> StgWord*

Missing { in mulIntCzh

Add two new operations to StgPrimFloat.c:

	__int_encodeFloat
	__int_encodeDouble

for encoding floats/doubles from small integers.  This avoids having
to convert small integers to large ones before an encodeFloat
operation, and fixes the two cases of slowdown in nofib after the
small integer changes.

Also:
	- remove encodeFloat and decodeFloat as primops
	- use foreign import for encode{Float,Double} and
	  the various isNaN etc. ccalls in PrelNumExtra.

Fast Integers.  The rep. of Integers is now

	data Integer = S# Int#
		     | J# Int# ByteArray#

- several new primops added for overflow-detecting arithmetic
- negateInteger# removed; it can be done directly
- integer_0, integer_1 etc. removed.
- the compiler now uses S# where it previously used int2Integer.
- the compiler generates small integers for -2^32 .. 2^32-1, instead
  of -2^29 .. -2^29-1.

- PrelST.State datatype moved to LazyST (its only use).
- some library code (in Time.lhs) still needs cleaning up, it depends
  on the Integer rep.

More finalise/finalize updates.

- s/finalise/finalize/g
- make finalize run the finalizer immediately, and wait for its completion
- make mkWeak take a (Maybe (IO ())) for the finalizer argument
- remove mkWeakNoFinalizer

Copyright police.

Remove MUT_ARR_WORDS.  I'm not sure why we had it in the first place.

Remove warnings in deRefWeakzh.

- Add finalise#
- Add mkWeakNoFinaliser
- Move deRefWeak# from an out-of-line primop to an inline one.

zh --> Zh (for genSymZh and resetGenSymZh)

Finally!  This commits the ongoing saga of Simon's hygiene sweep

FUNCTIONALITY
~~~~~~~~~~~~~
a) The 'unused variable' warnings from the renamer work.  
b) Better error messages here and there, esp type checker
c) Fixities for Haskell 98 (maybe I'd done that before)
d) Lazy reporting of name clashes for Haskell 98 (ditto)

HYGIENE
~~~~~~~
a) type OccName has its own module.  OccNames are represented
   by a single FastString, not three as in the last round.  This
   string is held in Z-encoded form; a decoding function decodes
   for printing in user error messages.  There's a nice tight
   encoding for (,,,,,,,,,,,,,,,,,,,,,,,,,,,,,)

b) type Module is a proper ADT, in module OccName

c) type RdrName is a proper ADT, in its own module

d) type Name has a new, somwhat tidier, representation

e) much grunting in the renamer to get Provenances right.
   This makes error messages look better (no spurious qualifiers)

- Add Stable Names

- Stable pointers and stable names are now both provided by the
  "Stable" module in ghc/lib/exts.  Documentation is updated, and Foriegn
  still exports the stable pointer operations for backwards compatibility.

integerToInt64Zh: didn't handle negative integers particularly well

Resurrect ticky-ticky profiling.  Not quite polished yet, but it
compiles and produces some reasonable-looking stats.

Remove debugging code from freeStablePtr.

Added debugging code to freeStablePtr macro

added isEmptyMVarZh macro

When -DDEBUG, in BYTE_ARR_CTS, allow GET_INFO(a) to be
&MUT_ARR_WORDS_info as well as &ARR_WORDS_info.

Added a generational garbage collector.

The collector is reliable but fairly untuned as yet.  It works with an
arbitrary number of generations: use +RTS -G<gens> to change the
number of generations used (default 2).

Stats: +RTS -Sstderr is quite useful, but to really see what's going
on compile the RTS with -DDEBUG and use +RTS -D32.

ARR_PTRS removed - it wasn't used anywhere.

Sanity checking improved:
	- free blocks are now spammed when sanity checking is turned on
	- a check for leaking blocks is performed after each GC.

Move 4.01 onto the main trunk.