Merge pull request #183 from zygoloid/float-mangle-grammar

Add missing grammar rule for `<float>`

abi.html

@@ -5763,6 +5763,10 @@ <h5><a href="#mangling.literal">5.1.6.1 Literals</a></h5>
 high-order bytes first.  For example: "Lf bf800000 E" is -1.0f on
 platforms conforming to IEEE 754.
 
+<a name="mangle.float">
+<pre><font color=blue><code>  &lt;float&gt; ::= &lt;<i>0-9a-f</i>&gt;+
+</pre></code></font>
+
 <p>
 The encoding for a literal of an enumerated type is the encoding of the
 type name followed by the encoding of the numeric value of the literal