merge revision(s) 57762: [Backport #13267]
broken mingw * configure.in: check whether frexp and modf are broken. * include/ruby/win32.h (frexp, modf): ignore bad declarations when compiling as C++. [ruby-core:79859] [Bug #13267]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57921 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 57762: [Backport #13267]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57921 b2dd03c8-39d4-4d8f-98ff-823fe69b080e