Fix:

* crashes on memory allocation failure found with failmalloc
 * memory leaks found with valgrind
 * compiler warnings in opt mode which would lead to invalid memory reads
 * problem using wrong name in decimal module reported by pychecker

Update the valgrind suppressions file with new leaks that are small/one-time
leaks we don't care about (ie, they are too hard to fix).

TBR=barry
TESTED=./python -E -tt ./Lib/test/regrtest.py -uall (both debug and opt modes)
  in opt mode:
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py -uall,-bsddb,-compiler \
                        -x test_logging test_ssl test_multiprocessing
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py test_multiprocessing
  for i in `seq 1 4000` ; do
    LD_PRELOAD=~/local/lib/libfailmalloc.so FAILMALLOC_INTERVAL=$i \
        ./python -c pass
  done

At least some of these fixes should probably be backported to 2.5.

Misc/valgrind-python.supp

@@ -46,6 +46,39 @@
 #    Will need to fix that.
 #
 
+{
+   Suppress leaking the GIL.  Happens once per process, see comment in ceval.c.
+   Memcheck:Leak
+   fun:malloc
+   fun:PyThread_allocate_lock
+   fun:PyEval_InitThreads
+}
+
+{
+   Suppress leaking the GIL after a fork.
+   Memcheck:Leak
+   fun:malloc
+   fun:PyThread_allocate_lock
+   fun:PyEval_ReInitThreads
+}
+
+{
+   Suppress leaking the autoTLSkey.  This looks like it shouldn't leak though.
+   Memcheck:Leak
+   fun:malloc
+   fun:PyThread_create_key
+   fun:_PyGILState_Init
+   fun:Py_InitializeEx
+   fun:Py_Main
+}
+
+{
+   Hmmm, is this a real leak or like the GIL?
+   Memcheck:Leak
+   fun:malloc
+   fun:PyThread_ReInitTLS
+}
+
 {
    Handle PyMalloc confusing valgrind (possibly leaked)
    Memcheck:Leak