With these changes, you can bind *print-base* to 16 and *print-case*
to :downcase to get correctly printed disassembly in lower case with
all numerical values in hex.  If you want the radix marker as well,
bind *print-radix* to T; the disassembly is still correct.

src/compiler/disassem.lisp:
o When printing out the source code, bind *print-base* to 10 so that
  the code is printed "naturally".

src/compiler/x86/insts.lisp:
o Use Carl's much cleaned-up print-mem-access
o Update print-imm-data to use princ for all values, removing the
  special casing for NIL
o When printing out xmm registers, honor *print-case*.

src/general-info/release-20e.txt:
o Update

try to set the source location information.  We try to print a warning
in such cases.

CLHS.

 src/contrib/asdf/asdf.lisp::
 * Update

 src/general-info/release-20e.txt::
 * Update

o Add release-20e.txt.

o Add release-20e.txt.