** MISC.564: defined out-of-line version of %ATAN2 on x86.
** attempting to create a package with a colliding nickname causes
correctable errors to be signalled.
+ ** MISC.572-574: :START1 and :START2 broken for simple-base-strings.
+ ** several x86-64 backend bugs related to sign-extension of immediate
+ operands.
changes in sbcl-0.8.20 (0.9alpha.0?) relative to sbcl-0.8.19:
* fixed inspection of specialized arrays. (thanks to Simon Alexander)