* autoload.cc (LoadDLLfuncEx3): Adjust address computation required
	by latest change to the 64 bit code.
	* cygmalloc.h (MALLOC_ALIGNMENT): Set to 16 on x86_64.
	* cygtls.h: Set struct alignment to 8 on x86_64.  Move inclusion of
	other header files outside of alignment-enforced code area.  Drop
	inclusion of security.h entirely.
	(_cygtls::get_signal_arrived): Use NULL SECURITY_ATTRIBUTES rather than
	&sec_none_nih.
	* gendef (_cygtls::lock): Fix stack alignment.
	* heap.cc (page_const): Change type to ptrdiff_t, otherwise negation
	operator in pround creates broken bitmask.
	* shared.cc (page_const): Add cast to ptrdiff_t.
	* tlsoffsets64.h: Regenerate.