* cygheap.cc (cfree): Remove malloc debugging probe.

* dlmalloc.c (errprint): Remove abort() call which causes interesting error
message printing to abort prematurely.
* environ.cc: Sprinkle MALLOC_CHECKs liberally throughout.
(_addenv): Allocate two empty elements at end of environ to
(apparently) work around problems with some buggy applications.
(winenv): Avoid calling alloca if no forced environment variable is present.

* exceptions.cc (open_stackdumpfile): Don't print "Dumping stack trace to..."
when running in a cygwin environment (i.e., the parent is a cygwin process).

* dtable.cc (dtable::init_std_file_from_handle): Move device type detection
code from build_fhandler here since it is only used by this function.
(dtable::build_fhandler_from_name): New method.  Renamed from
dtable::build_fhandler.
(dtable::build_fhandler): Use build_fhandler_from_name.
(cygwin_attach_handle_to_fd): Ditto.
* syscalls.cc (_open): Ditto.
(stat_worker): Ditto.
* dtable.h (dtable::build_fhandler_from_name): Rename declaration from
dtable::build_fhandler.

winsup/cygwin/dtable.h

@@ -50,9 +50,10 @@ public:
   void fixup_after_fork (HANDLE);
   fhandler_base *build_fhandler (int fd, DWORD dev, const char *name,
 				 int unit = -1);
-  fhandler_base *build_fhandler (int fd, const char *name, HANDLE h,
-      				 path_conv& pc, unsigned opts = PC_SYM_FOLLOW,
-				 suffix_info *si = NULL);
+  fhandler_base *build_fhandler_from_name (int fd, const char *name, HANDLE h,
+					   path_conv& pc,
+					   unsigned opts = PC_SYM_FOLLOW,
+					   suffix_info *si = NULL);
   inline int not_open (int fd)
   {
     SetResourceLock (LOCK_FD_LIST, READ_LOCK, "not_open");