0.8.20.30:

0.8.20.30:
	Slightly nicer behaviour on non-NPTL systems makes it possible
	to use thread-enabled binaries in thread-unfriendly environments again
	- but a warning is issued at startup and MAKE-THREAD signals an error

	Remove some slightly odd-looking stuff in make-config.sh: once
	again it is possible to "SBCL_ARCH=x86 sh make.sh" on an x86-64