+ * incompatible change: thread support for non-NPTL systems has
+ been removed - locking is buggy and unreliable. A threaded
+ SBCL build will now refuse to start unless futex support is
+ detected in the kernel
+ * incompatible change: the top level REPL now has only an ABORT
+ restart associated with it, not TOPLEVEL and ABORT as it used to.
+ TOP and TOPLEVEL are now available as debugger commands for
+ returning to the top level.
+ * incompatible change: forms evaluated in the REPL now use the
+ global optimization policy.
+ * incompatible change: user- and system-initialization files are
+ no longer processed with LOAD, but by READ and EVAL; hence the
+ global optimization policy, startup package, readtable, etc,
+ can be set by them.