configure.in: Werror-implicit-function-declaration
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39214 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.in: Werror-implicit-function-declaration
haven't been used as-is, but always replaced with -Werror= or -W.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39214 b2dd03c8-39d4-4d8f-98ff-823fe69b080e