test_regexp.rb, test_string.rb: use assert_separately

* test/ruby/test_regexp.rb (test_eq_tilde_can_be_overridden): use assert_separately
  to suppress a warning.
* test/ruby/test_string.rb (test_eq_tilde_can_be_overridden): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43104 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_regexp.rb, test_string.rb: suppress warnings

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43105 b2dd03c8-39d4-4d8f-98ff-823fe69b080e