+ * optimization: more efficient complex float and real float operations
+ on x86-64.
+ * optimization: division of a real float by a complex float is implemented
+ with a specialised code sequence.
+ * optimization: MAKE-INSTANCE with non-constant class-argument but constant
+ keywords is an order of magnitude faster.
+ * optimization: MAKE-INSTANCE with constant keyword arguments is x2-4 faster
+ in the presence of :AROUND or non-standard primary INITIALIZE-INSTANCE
+ methods, and similarly for non-standard metaclass classes as long as there
+ are no methods additional on MAKE-INSTANCE.