Empty entries in WP_Scripts 'extra' field

[vanyukov]

When WordPress registers all the scripts in wp_default_scripts() the add_inline_script() will often add false to the extra field of the script. That false value does not do anything and can be easily removed by comparing against empty data from get_data() in add_inline_script(). Doesn't look like this has any effect on anything, as false values will later on be ignored. But this will save a few extra bytes of memory.

Steps to verify:

• Get the $wp_scripts global
• Check some registered scripts, for example $wp_scripts->registered->editor->extra['after']. It will have two array values - one is false and one is the actual data window.wp.oldEditor = window.wp.editor;

Or via debugging by putting a breakpoint in wp-includes/class.wp-scripts.php in add_inline_script() for $script = (array) $this->get_data( $handle, $position );