envutil.rb: connect caller to backtrace

* test/ruby/envutil.rb (assert_separately): append current caller
  to backtrace show proper method name.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46198 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_dir_m17n.rb: assert_raw_file_name

* test/ruby/test_dir_m17n.rb (assert_raw_file_name): rename to
  show caller method in failure messages.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46199 b2dd03c8-39d4-4d8f-98ff-823fe69b080e