[css-text] test coverage

Author: frivoal

css-text-3/Overview.bs

@@ -1754,6 +1754,7 @@ Order of Operations</h4>
                white-space/white-space-intrinsic-size-014.html
                white-space/white-space-intrinsic-size-017.html
                white-space/eol-spaces-bidi-002.html
+               white-space/trailing-space-in-inline-box.html
              </wpt>
 
              Note: [=Hanging=] the white space rather than collapsing it