rustdoc: remove class name location from sidebar sibling nav

This change tweaks the CSS to apply most of its styles to `.sidebar h2`,
cleaning up a few redundant rules from `.mobile-topbar .location` and
restoring useful navigation aids in mobile mode.

src/librustdoc/html/render/mod.rs

@@ -1884,7 +1884,7 @@ fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
     if !it.is_mod() {
         let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
 
-        write!(buffer, "<h2 class=\"location\"><a href=\"index.html\">In {}</a></h2>", path);
+        write!(buffer, "<h2><a href=\"index.html\">In {}</a></h2>", path);
     }
 
     // Closes sidebar-elems div.

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

@@ -171,7 +171,7 @@ h1.fqn {
 	 Rustdoc-generated h2 section headings (e.g. "Implementations", "Required Methods", etc)
 	Underlines elsewhere in the documentation break up visual flow and tend to invert
 	section hierarchies. */
-h2,
+.content h2,
 .top-doc .docblock > h3,
 .top-doc .docblock > h4 {
 	border-bottom: 1px solid var(--headings-border-bottom-color);
@@ -397,15 +397,6 @@ img {
 	left: 0;
 }
 
-.sidebar-elems,
-.sidebar > .location {
-	padding-left: 24px;
-}
-
-.sidebar .location {
-	overflow-wrap: anywhere;
-}
-
 .rustdoc.source .sidebar {
 	width: 50px;
 	min-width: 0px;
@@ -504,8 +495,8 @@ ul.block, .block li {
 }
 
 .block a,
-.sidebar h3 a,
-h2.location a {
+.sidebar h2 a,
+.sidebar h3 a {
 	display: block;
 	padding: 0.25rem;
 	margin-left: -0.25rem;
@@ -515,8 +506,7 @@ h2.location a {
 }
 
 .sidebar h2 {
-	border-bottom: none;
-	font-weight: 500;
+	overflow-wrap: anywhere;
 	padding: 0;
 	margin: 0;
 	margin-top: 0.7rem;
@@ -525,11 +515,15 @@ h2.location a {
 
 .sidebar h3 {
 	font-size: 1.125rem; /* 18px */
-	font-weight: 500;
 	padding: 0;
 	margin: 0;
 }
 
+.sidebar-elems,
+.sidebar > h2 {
+	padding-left: 24px;
+}
+
 .sidebar a, .sidebar .current {
 	color: var(--sidebar-link-color);
 }
@@ -1798,18 +1792,10 @@ in storage.js plus the media query with (min-width: 701px)
 		width: 0;
 	}
 
-	.mobile-topbar .location a {
-		padding: 0;
-		margin: 0;
-	}
-
-	.mobile-topbar .location {
-		border: none;
-		padding: 0;
+	.mobile-topbar h2 {
+		padding-bottom: 0;
 		margin: auto 0.5em auto auto;
-		text-overflow: ellipsis;
 		overflow: hidden;
-		white-space: nowrap;
 		/* Rare exception to specifying font sizes in rem. Since the topbar
 		   height is specified in pixels, this also has to be specified in
 		   pixels to avoid overflowing the topbar when the user sets a bigger
@@ -1817,6 +1803,13 @@ in storage.js plus the media query with (min-width: 701px)
 		font-size: 24px;
 	}
 
+	.mobile-topbar h2 a {
+		display: block;
+		text-overflow: ellipsis;
+		overflow: hidden;
+		white-space: nowrap;
+	}
+
 	.mobile-topbar .logo-container {
 		max-height: 45px;
 	}

src/librustdoc/html/static/js/main.js

@@ -55,7 +55,7 @@ function blurHandler(event, parentElem, hideCallback) {
 function setMobileTopbar() {
     // FIXME: It would be nicer to generate this text content directly in HTML,
     // but with the current code it's hard to get the right information in the right place.
-    const mobileLocationTitle = document.querySelector(".mobile-topbar h2.location");
+    const mobileLocationTitle = document.querySelector(".mobile-topbar h2");
     const locationTitle = document.querySelector(".sidebar h2.location");
     if (mobileLocationTitle && locationTitle) {
         mobileLocationTitle.innerHTML = locationTitle.innerHTML;

src/librustdoc/html/templates/page.html

@@ -85,7 +85,7 @@
             {%- endif -%}
             </div> {#- -#}
         </a> {#- -#}
-        <h2 class="location"></h2> {#- -#}
+        <h2></h2> {#- -#}
     </nav> {#- -#}
     {%- endif -%}
     <nav class="sidebar"> {#- -#}