• The XSUB.h changes to make XS(name) use XS_INTERNAL(name)
  by default (which were in the 5.15.2 dev release of perl)
  have been reverted since too many CPAN modules expect to
  be able to refer to XSUBs declared with XS(name).
  Instead, ExtUtils::ParseXS will define a copy of the
  XS_INTERNAL/XS_EXTERNAL macros as necessary going back to
  perl 5.10.0 (which is the oldest perl I had for testing).
  By default, ExtUtils::ParseXS will use XS_INTERNAL(name)
  instead of XS(name).