changes in sbcl-1.4.9 relative to sbcl-1.4.8:
* enhancement: SB-COVER instrumentation for x86[-64] has signficantly less
overhead. The performance penalty for 64-bit code has been measured at
around 30% slower than uninstrumented code as contrasted with slowdowns
in excess of 100% previously.
* enhancement: tracing a generic function with the :METHODS T option
produces output corresponding to each method called under the default
:ENCAPSULATE NIL tracing implementation.
* bug fix: updated TRACE documentation. (lp#574614 was actually already
fixed, but there were other issues.)
* bug fix: fixed x86 GC bug causing heap corruption. (lp#1749369)
* bug fix: improved compatibility with macOS High Sierra and graphical
applications.