changes in sbcl-2.1.3 relative to sbcl-2.1.2:
* minor incompatible change: support for the :SB-SAFEPOINT-STRICTLY,
:SB-THRUPTION, and :SB-WTIMER build features has been removed
* platform support:
** support for :SB-CORE-COMPRESSION on Darwin/ARM64
** support ARM v8.1 atomic and compare-and-swap instructions
** x86, x86-64: microoptimizations in multiple type-checking routines
* bug fix: structures and conditions are now TYPEP all classes in the class
precedence list of their class. (reported by Luis Oliveira)
* bug fix: derivation of the result type from subtraction sometimes
erroneously excluded zero. (lp#1916895)
* bug fix: reduce the number of places where the system permissively accepts
* as a type specifier where it should not be accepted. (lp#1860919)
* bug fix: the code-walker used by the system's implementation of CLOS can
handle defuns declared inline. (reported by Don Cohen)
* optimization: EQUALP on specialized vectors and arrays is faster.
* optimization: support routines for EQUALP hash tables generate less garbage.