merge revision(s) 64915: [Backport #15205]
check argument type. * iseq.c (iseqw_s_compile): check argument type (T_STRING) to avoid SEGV.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@64978 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 64915: [Backport #15205]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@64978 b2dd03c8-39d4-4d8f-98ff-823fe69b080e