Enum type interpreted as function name

[marxin]

Describe the bug

In the following example:

.. function:: enum gimple_code gimple_code (gimple g)

  Return the code for statement ``G``.

There's a wrongly created a hyperlink to the function (after enum keyword):

How to Reproduce

Build the snippet.

Expected behavior

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Your project

Build the snippet

Screenshots

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OS

Linux

Python version

3.8

Sphinx version

4.3.1

Sphinx extensions

No response

Extra tools

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Additional context

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[jakobandersen]

I think this is a duplicate of #7740.
The current xref lookup in both the C++ and C domains currently only use the parent symbol as reference, not the relative position inside each declaration.
Additionally, neither domain yet makes a difference between tagged names and ordinary identifiers. For the C domain there is #8313 which was stalled due to breakage of intersphinx lookups.