Build/Test Tools: Replace the banner text from `wp-emoji-loader.min.js` in `formatting.php` during build process.

This ensures that `/*! This file is auto-generated */` comment is not included on front end as part of the inline Emoji detection script.

Follow-up to [41271], [46589].

Props superpoincare, SergeyBiryukov.
Fixes #49861.

git-svn-id: https://develop.svn.wordpress.org/trunk@48096 602fd350-edb4-49c9-b593-d223f7449a82

Gruntfile.js

@@ -1097,6 +1097,26 @@ module.exports = function(grunt) {
 						dest: SOURCE_DIR + 'wp-includes/'
 					}
 				]
+			},
+			emojiBannerText: {
+				options: {
+					patterns: [
+						{
+							match: new RegExp( '\\s*' + BANNER_TEXT.replace( /[\/\*\!]/g, '\\$&' ) ),
+							replacement: ''
+						}
+					]
+				},
+				files: [
+					{
+						expand: true,
+						flatten: true,
+						src: [
+							BUILD_DIR + 'wp-includes/formatting.php'
+						],
+						dest: BUILD_DIR + 'wp-includes/'
+					}
+				]
 			}
 		},
 		_watch: {
@@ -1419,6 +1439,7 @@ module.exports = function(grunt) {
 				'build:css',
 				'includes:emoji',
 				'includes:embed',
+				'replace:emojiBannerText'
 			] );
 		}
 	} );