rustdoc: short descr. cause word-breaks in tables

The `.item-table` class is used to display name+description lists, e.g.
the exported functions, as a table. If the names are long and the
descriptions are short, then the width of the table does not expand to
the whole size, but only uses a fraction. This causes a some names to
break inside a word.

This change makes the table always use 100% of its parent width. The
`.width-limiter` wrapper already ensures that the used width still does
not become excessive.

Signed-off-by: René Kijewski <rene.kijewski@fu-berlin.de>

src/librustdoc/html/static/css/rustdoc.css

@@ -953,6 +953,7 @@ table,
 	display: table;
 	padding: 0;
 	margin: 0;
+	width: 100%;
 }
 .item-table > li {
 	display: table-row;