proc.c: documentation for Proc#{call,yield,[]}
* proc.c: [DOC] fix and improve docs for Proc#{call,yield,[]}:
* change order of Document-method directives as workaround for an
RDoc rendering problem where the documentation for Proc#call displays
a "Document-method: []" code block. [ruby-core:79887] [Bug #13273]
* add missing call-seq and example for Proc#yield
* remove pointless cross reference to Proc#yield
* update description for handling of extra or missing arguments,
improve examples and add cross reference to #lambda?
merge revision(s) 57765: [Backport #13273]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@58185 b2dd03c8-39d4-4d8f-98ff-823fe69b080e