* bug fix: some GC deadlocks caused by asynchronous interrupts have
been fixed by inhibiting interrupts for when GC is disbled.
* bug fix: GETHASH, PUTHASH, CLRHASH and REMHASH are now interrupt safe.
+ * bug fix: binding *BREAK-ON-SIGNALS* to a value that is not a type
+ specifier no longer causes infinite recursion.
* improvement: the x86-64/darwin port now passes all tests and
should be considered non-experimental.