Add support for warning section

Author: GuillaumeGomez

src/librustdoc/html/static/rustdoc.css

@@ -332,10 +332,23 @@ nav.sub {
 
 .rustdoc:not(.source) .example-wrap {
 	display: inline-flex;
+}
+.rustdoc:not(.source) .example-wrap, #main div.rustdoc-warning {
 	margin-bottom: 10px;
 	position: relative;
 }
 
+#main div.rustdoc-warning {
+	padding: 10px;
+	border-left: 2px solid;
+}
+#main div.rustdoc-warning::before {
+	content: "⚠";
+	position: absolute;
+	left: -25px;
+	font-size: 20px;
+}
+
 .example-wrap {
 	width: 100%;
 }

src/librustdoc/html/static/themes/ayu.css

@@ -53,7 +53,7 @@ span code {
 .docblock code, .docblock-short code {
 	background-color: #191f26;
 }
-pre {
+pre, #main div.rustdoc-warning {
 	color: #e6e1cf;
 	background-color: #191f26;
 }
@@ -336,6 +336,13 @@ a.test-arrow:hover {
 	border-right: 3px solid rgba(255, 180, 76, 0.85);
 }
 
+#main div.rustdoc-warning {
+	border-left-color: #f00;
+}
+#main div.rustdoc-warning::before {
+	color: #f00;
+}
+
 pre.compile_fail {
 	border-left: 2px solid rgba(255,0,0,.4);
 }

src/librustdoc/html/static/themes/dark.css

@@ -26,7 +26,7 @@ h4:not(.method):not(.type):not(.tymethod) {
 .docblock code, .docblock-short code {
 	background-color: #2A2A2A;
 }
-pre {
+pre, #main div.rustdoc-warning {
 	background-color: #2A2A2A;
 }
 
@@ -285,6 +285,13 @@ a.test-arrow:hover{
 	border-right: 3px solid #bb7410;
 }
 
+#main div.rustdoc-warning {
+	border-left-color: #f00;
+}
+#main div.rustdoc-warning::before {
+	color: #f00;
+}
+
 pre.compile_fail {
 	border-left: 2px solid rgba(255,0,0,.8);
 }

src/librustdoc/html/static/themes/light.css

@@ -28,7 +28,7 @@ h4:not(.method):not(.type):not(.tymethod) {
 .docblock code, .docblock-short code {
 	background-color: #F5F5F5;
 }
-pre {
+pre, #main div.rustdoc-warning {
 	background-color: #F5F5F5;
 }
 
@@ -277,6 +277,13 @@ a.test-arrow:hover{
 	border-right: 3px solid #ffb44c;
 }
 
+#main div.rustdoc-warning {
+	border-left-color: #f00;
+}
+#main div.rustdoc-warning::before {
+	color: #f00;
+}
+
 pre.compile_fail {
 	border-left: 2px solid rgba(255,0,0,.5);
 }