Replace property_exists call in block api with instanceof

[spacedmonkey]

Remove calls this in block functions

property_exists( $block_type, 'supports' ) 

with

$block_type instanceof WP_Block_Type

Trac ticket: https://core.trac.wordpress.org/ticket/59453#ticket

[spacedmonkey]

There are performance benefits and code quality to this improvement.

[flixos90]

@spacedmonkey Could you share some benchmarks or profiles here in regards to the performance impact?

[gziolo]

I'm not entirely sure how backporting works for these files, but it's worth emphasizing that the same code lives in the Gutenberg plugin in ​https://github.com/WordPress/gutenberg/tree/trunk/lib/block-supports. I'm sure these files aren't copied automatically, but if you agree on the changes, we will have to apply the same set of changes in the Gutenberg plugin. I can see how these changes would improve performance by using language constructs like instanceof and isset.

A separate discussion would be how to make it easier to sync code between WordPress core and Gutenberg for block supports.

[spacedmonkey]

Guterberg PR - ​https://github.com/WordPress/gutenberg/pull/54835

[spacedmonkey]

In 56742:

Editor: Replace property_exists calls in block related functions with instanceof

Replace calls to property_exists with instanceof WP_Block_Type in block related functions. This change not only improves type safety but also enhances performance.

Follow on from [56678] and [56677].

Props gziolo, aristath, aaronrobertshaw, spacedmonkey.
Fixes #59453

Committed https://core.trac.wordpress.org/changeset/56742