Replace _x() with __() to merge similar translation strings wp-includes/post-template.php

[ramiy]

Context function _x() is used to differ two similar strings with different meanings.

This patch is replacing the context _x() function with regular __() function to merge those strings. And avoid wrong usage of context functions.

Those are similar translation strings. They should be merged. The only difference is the %s placeholder. We document this difference in translators comments, not as a context.

See the attached screenshot from translate.wordpress.org and the attached patch.

[SergeyBiryukov]

In 38324:

I18N: Replace unnecessary context with translator comments in wp_post_revision_title() and wp_post_revision_title_expanded().

Props ramiy.
Fixes #37778.