Ruby » Ruby master

merge revision(s) a6a26e42b15c46f117f4fce07a2050e9d727355d: [Backport #15906]

    compile.c: Partially revert r63870 which caused wrong optimization
    [Bug #15906]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@67757 b2dd03c8-39d4-4d8f-98ff-823fe69b080e