Rollup merge of rust-lang#109977 - notriddle:notriddle/data-nosnippet, r=jsha,the8472

rustdoc: avoid including line numbers in Google SERP snippets

![image](https://user-images.githubusercontent.com/1593513/230141184-9171c8e0-de92-48e6-85b6-8baee35e6d86.png)

Author: matthiaskrgr

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

@@ -352,7 +352,7 @@ pre.item-decl {
 .source .content pre {
 	padding: 20px;
 }
-.rustdoc.source .example-wrap > pre.src-line-numbers  {
+.rustdoc.source .example-wrap pre.src-line-numbers  {
 	padding: 20px 0 20px 4px;
 }
 
@@ -537,17 +537,17 @@ ul.block, .block li {
 	margin-bottom: 0px;
 }
 
-.rustdoc .example-wrap > pre {
+.rustdoc .example-wrap pre {
 	margin: 0;
 	flex-grow: 1;
 }
 
-.rustdoc:not(.source) .example-wrap > pre {
+.rustdoc:not(.source) .example-wrap pre {
 	overflow: auto hidden;
 }
 
-.rustdoc .example-wrap > pre.example-line-numbers,
-.rustdoc .example-wrap > pre.src-line-numbers {
+.rustdoc .example-wrap pre.example-line-numbers,
+.rustdoc .example-wrap pre.src-line-numbers {
 	flex-grow: 0;
 	min-width: fit-content; /* prevent collapsing into nothing in truncated scraped examples */
 	overflow: initial;
@@ -558,7 +558,7 @@ ul.block, .block li {
 	color: var(--src-line-numbers-span-color);
 }
 
-.rustdoc .example-wrap > pre.src-line-numbers {
+.rustdoc .example-wrap pre.src-line-numbers {
 	padding: 14px 0;
 }
 .src-line-numbers a, .src-line-numbers span {
@@ -706,7 +706,7 @@ h2.small-section-header > .anchor {
 }
 
 .main-heading a:hover,
-.example-wrap > .rust a:hover,
+.example-wrap .rust a:hover,
 .all-items a:hover,
 .docblock a:not(.test-arrow):not(.scrape-help):not(.tooltip):hover,
 .docblock-short a:not(.test-arrow):not(.scrape-help):not(.tooltip):hover,

src/librustdoc/html/templates/source.html

@@ -1,13 +1,15 @@
 <div class="example-wrap"> {# #}
-    <pre class="src-line-numbers">
+    {# https://developers.google.com/search/docs/crawling-indexing/robots-meta-tag#data-nosnippet-attr
+       Do not show "1 2 3 4 5 ..." in web search results. #}
+    <div data-nosnippet><pre class="src-line-numbers">
         {% for line in lines.clone() %}
             {% if embedded %}
                 <span>{{line|safe}}</span>
             {%~ else %}
                 <a href="#{{line|safe}}" id="{{line|safe}}">{{line|safe}}</a>
             {%~ endif %}
         {% endfor %}
-    </pre> {# #}
+    </pre></div> {# #}
     <pre class="rust"> {# #}
         <code>
             {% if needs_expansion %}