Describe the bug
Some domain directives generate wrong target ID. For example, both py:module and js:module generate target IDs with wrong operation. So they might be conflicted.

To Reproduce

This input are converted to following:

blah blah blah

.. js:module:: foo

blah blah blah

.. py:module:: foo

blah blah blah

<p>blah blah blah</p>
<span class="target" id="module-foo"></span><p>blah blah blah</p>
<span class="target" id="module-foo"></span><p>blah blah blah</p>

Expected behavior
All domain directives generate valid target IDs and they are not conflicted.

Your project
N/A

Screenshots
N/A

Environment info

• OS: Mac
• Python version: 3.8.0
• Sphinx version: 2.2.2
• Sphinx extensions: N/A