GETF, LOGBITP, LDB, and MASK-FIELD now arrange for non-primary values
of multiple-valued places to be set to NIL, instead of signalling an
error (per a careful reading of CLHS 5.1.2.3).
+ * bug fix: floating-point traps now work on darwin/x86-64.
changes in sbcl-1.0.52 relative to sbcl-1.0.51:
* enhancement: ASDF has been updated to version 2.017.