0.pre8.40

0.pre8.40
		  === Threads merge, 0.390625 metres ===

	Unithread fixes for all remaining architectures, although I'm
	not 100% that BSD ports are all working.

	Various 32/64 bit fixes for Alpha

	Removed the allocate-16Mb-at-a-time hacks from the Linux port,
	substitute with MAP_NORESERVE: CMUCL has been doing this for a
	long time already without user complaint.  Also the retryable
	mmap errors: as there's no logic in the caller to actually
	retry, we'd be better off losing if mmap fails.