changes in sbcl-2.0.8 relative to sbcl-2.0.7:
* platform support:
** added support for NetBSD/ARM64;
** threads on Linux now have OS-visible names;
** removed unnecessary emulation of pthread functions on Windows;
** work around a sigwait() bug on Mac OS X;
** allow safepoint build on Mac OS X, though it probably doesn't
work very well (reported by Chris Wagner, lp#1382811)
** removed stub support for HPUX.
* optimization: SB-THREAD:MAKE-THREAD is faster on most platforms.
* optimization: faster RATIONAL when the result is a RATIO.
* optimization: improved cross-type comparisons (float/ratio/bignum).
* bug fix: EQUALP on pathnames was wrong
* bug fixes: fix compiler issues in:
** COUNT (lp#1889391)
** VECTOR-LENGTH (lp#1888919)
** constant-folding (lp#1888384)
** FIND and POSITION (lp#1887316)