make validate happy

oops, it's i386_TARGET_ARCH, not x86_TARGET_ARCH

SMP bugfix: if the thread we were just running blocked, then we are in
a delicate state - we don't necessarily have access to the TSO we were
just running, because we relinquished it when we put it on whatever
blocking queue it is on.  It might even be running already.

Previously I made the scheduler quickly loop again in this case.
However, I made it loop too quickly: we should be sure to set the
blackholes_need_checking flag if necessary, otherwise we can miss some
wakeups.

more docs for GHC_PACKAGE_PATH

when GHC_PACKAGE_PATH is set, treat the database at the bottom of the
stack as the "global" one, ie. the one we modify by default.  This
means that GHC_PACKAGE_PATH can be used to set up a virtual GHC
package environment into which packages can be installed using Cabal,
without setting anything other than GHC_PACKAGE_PATH.

gcc's -fstrict-aliasing is biting us when we use the stack to store
different types of objects.  For example:

  *((StgDouble*)((W_)Sp-8)) = *((StgDouble*)((W_)Sp+8));
  Sp[1] = (W_)&s1Cx_info;

gcc feels free to reorder these two lines, because they refer to
differently typed objects, even though the assignment to Sp[1] clearly
aliases the read from the same location.

Trying to fix this by accessing locations using union types might be
possible, but I took the sledgehammer approach of
-fno-strict-aliasing.  This is justified to a certain extent because
our generated C code is derived from a very weakly-typed internal
language (C--).

unless I'm mistaken, only x86 needs -ffloat-store.  x86_64 certainly
doesn't need it, because it uses SSE2 with the correct-sized floating
point registers and doesn't store temporary results with more
precision than results in memory.

Fix bug in an assertion

raiseAsync: fix bug that can cause a scavenge_stack panic for a thread
that has just been killed.

Fix some problems with array thawing/freezing and the GC.

Fix non-threaded build.

fix for pre-6.0 ghc's

Document GHC_PACKAGE_PATH, and changes to the ghc-pkg command line interface.

- Add support for the GHC_PACKAGE_PATH environment variable, which
  specifies a :-separated (;-separated on Windows) list of package
  database files.  If the list ends in : (; on Windows), then the
  normal user and global databases are added.

  GHC_PACKAGE_PATH is searched left-to-right for packages, like
  $PATH, but unlike -package-conf flags, which are searched
  right-to-left.  This isn't ideal, but it seemed the least worst to me
  (command line flags always override right-to-left (except -i),
  whereas the PATH environment variable overrides left-to-right, I chose
  to follow the environment variable convention).  I can always change
  it if there's an outcry.

- Rationalise the interpretation of --user, --global, and -f on the
  ghc-pkg command line.  The story is now this: --user and --global
  say which package database to *act upon*, they do not change the
  shape of the database stack.  -f pushes a database on the stack, and
  also requests that the specified database be the one to act upon, for
  commands that modify the database.  If a database is already on the stack,
  then -f just selects it as the one to act upon.

  This means you can have a bunch of databases in GHC_PACKAGE_PATH, and
  use -f to select the one to modify.

patch up forkProcess(): don't discard our own Task, and set
cap->spare_workers to be empty in the child process.

We shouldn't call closeCondition() on the condition in discardTask(),
we're just freeing the Task for later use.

Win32: Use CriticalSections instead of Mutexes, they are *much* faster.

adjust type of startSignalHandlers() to make changes to Win32 version

schedulePushWork(): don't attempt to move the thread bound to the
current Task to a different Capability.

wibble

Improve the Win32 implementation of the time-measurement stuff.  Now
supports per-thread CPU time, and the elapsed time should be correct
(previously it was the sum of user time & kernel time, which isn't
what we want).

use getThreadCPUTime, not getProcessTimes

Fixes for console event handling on Win32 in the threaded/SMP runtime.
(it now builds, but is untested).

Missing import for new assert

Modify ACQUIRE_LOCK/RELEASE_LOCK for use in .cmm files

avoid a warning

Fix build on win32.

Improvments to time-measurement and stats:

  - move all the platform-dependent timing related stuff into
    posix/GetTime.c and win32/GetTime.c, with the machine-indepent
    interface specified in GetTime.h.  This is now used by
    Stats.c.

  - On Unix, use gettimeofday() and getrusage() by default, falling
    back to time() if one of these isn't available.

  - try to implement thread-specfic CPU-time measurement using
    clock_gettime() on Unix.  Doesn't work reliably on Linux, because
    the implemenation tries to use the processor TSC, which on an
    SMP machine goes wrong when the thread moves between CPUs.  However,
    it's slightly less bogus that before, and hopefully will improve
    in the future.

indentation only

Check for librt and clock_gettime()

Second correction to the TH fix of Oct 26, involving thFAKE

Original message
  1) A bug in the renaming of [d| brackets |]. The problem was
  that when we renamed the bracket we messed up the name cache, because
  the module was still that of the parent module. Now we set a fake
  module before renaming it.

This commit fixes the typecheker problem in a different way,
in tcLookupGlobal.

Trace output only

release/acquire the SM lock around scheduleFinalizers(), because we
need to call allocateLocal() in there, which acquires the SM lock.

when shutting down, don't allow a worker to exit until the run queue
is empty, because the thread in exitScheduler() is waiting for this.

scheduleHandleStackOverflow: fix bug in non-threaded RTS - if
(task->tso != NULL), then (task->tso) is not necessarily the TSO we
are running (in the threaded RTS it is).

Also fix a few non-threaded warnings while I'm here.

add an ASSERT

Fix warnings when assigning the result of a foreign call to BaseReg
(as now happens in SMP mode with resumeThread()).

Correct the TH fix of Oct 26, involving thFAKE
		MERGE TO STABLE

Original message
  1) A bug in the renaming of [d| brackets |]. The problem was
  that when we renamed the bracket we messed up the name cache, because
  the module was still that of the parent module. Now we set a fake
  module before renaming it.

But we have to tell the *typechecker* too, not just the renamer.
See comments with TcSplice.tc_bracket (DecBr case).

Should fix TH failures in the STABLE branch

Export lists

x86_64: pass -fno-unit-at-a-time to gcc.  See comment for details.