Add frewscxv's regression test for whitespace in <input>

tests/html/input_whitespace_regression.html

@@ -0,0 +1,7 @@
+
+Both input elements below should have more than one space between "foo" and "bar":
+
+<form>
+<input value="foo     bar">
+<input value="foo&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;bar">
+</form>