2006-04-28 Hans Boehm <Hans.Boehm@hp.com>

2006-04-28  Hans Boehm <Hans.Boehm@hp.com>
	* NT_STATIC_THREADS_MAKEFILE: Assorted cleanups and bug fixes for VC++.net
	* mark.c (alloc_mark_stack): Recycle old stack only if it doesn't break
	GWW_VDB.
	* misc.c: Try to initialize GWW_VDB earlier.  Remove seemingly obsolete
	initialization code.  More consistently use GC_LOF_FILE.
	* os_dep.c (GC_unix_get_mem): Ensure sbrk lock release on Irix, even in the
	really obscure cases.
	Fix GetWriteWatch error handling; work around slightly late calls to
	GC_enable_incremental().