Auto merge of #84552 - GuillaumeGomez:open-impl-blocks-by-default, r=jsha

Open impl blocks by default

Fixes #84558.
Part of #84422.

As you can see on https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TyCtxt.html, impl blocks are currently not open by default whereas they should.

I also realized that a test was outdated so I removed it and opened #84550 because it seems like the rustdoc-gui test suite isn't run on CI...

cc `@jyn514`
r? `@jsha`

src/test/rustdoc-gui/hash-item-expansion.goml

@@ -0,0 +1,18 @@
+// This test ensures that the element corresponding to the hash is displayed.
+goto: file://|DOC_PATH|/struct.Foo.html#method.borrow
+// In the blanket implementations list, "Borrow" is the second one, hence the ":nth(2)".
+assert: ("#blanket-implementations-list > details:nth-child(2)", "open", "")
+// Please note the "\" below is needed because otherwise ".borrow" would be interpreted as
+// a class selector.
+assert: ("#method\.borrow", {"display": "flex"})
+// We first check that the impl block is open by default.
+assert: ("#implementations + details", "open", "")
+// We collapse it.
+click: "#implementations + details > summary"
+// We check that it was collapsed as expected.
+assert-false: ("#implementations + details", "open", "")
+// To ensure that we will click on the currently hidden method.
+assert: (".sidebar-links > a", "must_use")
+click: ".sidebar-links > a"
+// We check that the impl block was opened as expected so that we can see the method.
+assert: ("#implementations + details", "open", "")

src/test/rustdoc-gui/impl-default-expansion.goml

@@ -0,0 +1,3 @@
+// This test ensures that the impl blocks are open by default.
+goto: file://|DOC_PATH|/struct.Foo.html
+assert: ("#main > details.implementors-toggle", "open", "")

src/test/rustdoc-gui/nojs-attr-pos.goml

@@ -1,5 +0,0 @@
-// Check that the attributes are well positioned when javascript is disabled (since
-// there is no toggle to display)
-javascript: false
-goto: file://|DOC_PATH|/struct.Foo.html
-assert: (".attributes", {"margin-left": "0px"})