Manipulation: blacklist IE8 from running tests for tag-hyphenated elems

IE8 supports only HTML elements it knows about, but if user uses custom
elements a.k.a. tag-hyphenated, we assume it doesn't try to use them with IE8

Ref 5d522f5c

test/unit/manipulation.js

@@ -529,6 +529,13 @@ test( "html(String) with HTML5 (Bug #6485)", function() {
 
 test( "html(String) tag-hyphenated elements (Bug #1987)", function() {
 
+	// Support: IE8
+	if ( /msie 8\.0/i.test( navigator.userAgent ) ) {
+		expect( 1 );
+		ok( true, "IE8 doesn't support custom elements" );
+		return;
+	}
+
 	expect( 27 );
 
 	jQuery.each( "thead tbody tfoot colgroup caption tr th td".split(" "), function( i, name ) {