remove reference to "basic literal" since it's never defined

R=rsc, r
CC=golang-dev
https://golang.org/cl/183113

doc/go_spec.html

@@ -179,7 +179,8 @@ into the token stream at the end of a non-blank line if the line's final
 token is
 </p>
 <ul>
-	<li>an identifier or basic literal
+	<li>an identifier
+	<li>an integer, floating-point, character, or string literal
 	<li>one of the keywords
 	    <code>break</code>, <code>continue</code>, <code>fallthrough</code>,
 	    or <code>return</code>