dln.c: fix EXTERNAL_PREFIX
configure.in (EXPORT_PREFIX): revert r50410.
dln.c (EXTERNAL_PREFIX): define by predefined macros. configured EXPORT_PREFIX is different thing.
win32/Makefile.sub: r50414-50415.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50416 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dln.c: fix EXTERNAL_PREFIX
configure.in (EXPORT_PREFIX): revert r50410.
dln.c (EXTERNAL_PREFIX): define by predefined macros.
configured EXPORT_PREFIX is different thing.
win32/Makefile.sub: r50414-50415.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50416 b2dd03c8-39d4-4d8f-98ff-823fe69b080e