* configure.ac (MALLOC_OFILES): Add ptmalloc3.o.
	* configure: Regenerate.
	* cygmalloc.h: Declare pt* functions rather than dl* functions.
	(mmap64): Declare.
	(mmap): Define as mmap64.
	(__malloc_lock): Drop macro.
	(__malloc_unlock): Ditto.
	(MSPACES): Define.
	(ONLY_MSPACES): Define.
	* debug.h: Include malloc.h rather than otherwise unused dlmalloc.h.
	* fork.cc (frok::parent): Drop malloc locking since that's performed
	by malloc_atfork now.
	* heap.cc (heap_init): Accommodate the fact that there's a chance
	that no heap space has been allocated at fork time.
	* malloc-private.h: New file from ptmalloc3, having malloc-machine.h
	and malloc-2.8.3.h folded in.
	* malloc.cc: Replaced by new file from ptmalloc3.
	* malloc_wrapper.cc: Throughout, remove malloc locks and call pt*
	functions rather than dl* functions.
	* pinfo.cc (winpids::set): Drop malloc locking.
	* ptmalloc3.cc: New file from ptmalloc3.
	* include/cygwin/signal.h (struct ucontext): Add missing fields from
	Windows CONTEXT definition.  Define oldmask as 64 bit type.
	* exceptions.cc (_cygtls::signal_debugger): Raise size of sigmsg buffer
	on x86_64.
	* tlsoffsets64.h: Regenerate.
	* pseudo-reloc.cc (do_pseudo_reloc): Add test to check for invalid 32
	bit relocation in 64 bit code.  Only test when building without
	optimization.
	* libc/include/machine/setjmp.h (sigjmp_buf): Fix definition of
	sigjmp_buf size if _JBTYPE is defined.

	* libc/include/machine/setjmp.h: Revert definition of _JBTYPE and _JBLEN
	for 64 bit Cygwin to use long as base type.  Drop unneeded comment.