Fix scrollbars appearing on information tooltip on mac when they shouldn't

Author: GuillaumeGomez

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

@@ -532,7 +532,7 @@ nav.sub {
 	position: relative;
 }
 
-.docblock > * {
+.docblock > :not(.information) {
 	max-width: 100%;
 	overflow-x: auto;
 }

src/test/rustdoc-gui/overflow-tooltip-information.goml

@@ -0,0 +1,8 @@
+// The goal of this test is to ensure that the tooltip `.information` class doesn't
+// have overflow and max-width CSS rules set because they create a bug in firefox on
+// mac. For more information: https://github.com/rust-lang/rust/issues/89185
+goto: file://|DOC_PATH|/test_docs/fn.foo.html
+assert-css: (".docblock > .information", {
+    "overflow-x": "visible",
+    "max-width": "none"
+}, ALL)