configure.in: remove options from comments

* configure.in (RUBY_APPEND_OPTION, RUBY_APPEND_OPTIONS),
  (RUBY_PREPEND_OPTION, RUBY_PREPEND_OPTIONS): remove option
  lists, which can be multiple lines, from generated comments.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44296 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.in: use RUBY_APPEND_OPTIONS

* configure.in: DLDFLAGS is defined in --with-opt-dir handler, so
  ${DLDFLAGS=} does not work now.  use RUBY_APPEND_OPTIONS instead.
  [ruby-dev:47855] [Bug #9256]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44297 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* include/ruby/ruby.h: add a comment for WB interfaces.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44298 b2dd03c8-39d4-4d8f-98ff-823fe69b080e