changes in sbcl-2.1.6 relative to sbcl-2.1.5:
* minor incompatible change: COMPILE-FILE does not merge the input file's
pathname-directory into the output path if :OUTPUT-FILE was specified
and has a directory that is not :UNSPECIFIC.
* platform support:
** improvements to unwind code generation on arm64.
** on x86-64, accept three operands for vshufpd. (reported by Bela
Pecsek)
** on x86-64, improvements to use of popcount
** improve exception handling on 64-bit Windows. (thanks to Luis Borges
de Oliveira)
* bug fix: allow use of macros with improper argument list. (lp#1929623,
thanks to Sean Maher)
* bug fix: COERCE no longer attempts to guess what the user meant if they
provide a type specifier of a union of types other than STRING.
(lp#1929614)
* bug fix: print a single trailing zero after the decimal point for FORMAT
~E if there are no digits remaining to be printed and the width allows it.
(lp#883520)