string.c: rb_str_symname_p
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35987 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: rb_str_symname_p
is valid as a symbol name. split from sym_inspect().
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35987 b2dd03c8-39d4-4d8f-98ff-823fe69b080e