Suppress warnings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35902 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/-test-/string/coderange.c

@@ -15,6 +15,7 @@ str_coderange(VALUE str)
       case ENC_CODERANGE_BROKEN:
 	return sym_broken;
     }
+    rb_bug("wrong condition of coderange");
     UNREACHABLE;
 }