Commit 54bbe0b284 inadvertently led
psyntax to dismiss source location info for data returned by read hash
extensions, because read hash extensions return plain data with
associated source properties, even when called from 'read-syntax'.
This change reverts part of this commit to restore that behavior.
Fixes <https://issues.guix.gnu.org/54003>.
* module/ice-9/psyntax.scm (datum-sourcev): New procedure.
(source-annotation): Fall back to 'datum-sourcev'.
* module/ice-9/psyntax-pp.scm: Regenerate.
* test-suite/tests/compiler.test ("psyntax")["syntax-source with
read-hash-extend"]: New test.