merge revision(s) 53485: [Backport #11976]

* symbol.h (is_attrset_id): ASET is an attrset ID.  fix
	  unexpected safe call instead of an ordinary ASET.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@54396 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_call.rb

@@ -83,4 +83,11 @@ class TestCall < Test::Unit::TestCase
   def test_safe_call_block_call_command
     assert_nil(("a".sub! "b" do end&.foo 1 do end))
   end
+
+  def test_invalid_safe_call
+    h = nil
+    assert_raise(NoMethodError) {
+      h[:foo] = nil
+    }
+  end
 end