Add test for rust-lang#112901

It's a lot of snapshots, but it's quite hard to test this sort of
formatting with other ways.

tests/rustdoc/issue-112901-where-clause.assoc-S-impl-F.html

@@ -0,0 +1,3 @@
+<section id="associatedtype.F" class="associatedtype trait-impl"><a href="#associatedtype.F" class="anchor">&#167;</a><h4 class="code-header">type <a href="trait.Tr.html#associatedtype.F" class="associatedtype">F</a>&lt;T&gt; = T
+<span class="where">where
+    T: <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a></span></h4></section>

tests/rustdoc/issue-112901-where-clause.assoc-Tr-F.html

@@ -0,0 +1,3 @@
+<section id="associatedtype.F" class="method"><a class="srclink rightside" href="../../src/foo/issue-112901-where-clause.rs.html#28-30">source</a><h4 class="code-header">type <a href="#associatedtype.F" class="associatedtype">F</a>&lt;T&gt;
+<span class="where">where
+    T: <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a></span></h4></section>

tests/rustdoc/issue-112901-where-clause.assoc-Tr-decl.html

@@ -0,0 +1,5 @@
+<pre class="rust item-decl"><code>pub trait Tr {
+    type <a href="#associatedtype.F" class="associatedtype">F</a>&lt;T&gt;
+    <span class="where">where
+        T: <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a></span>;
+}</code></pre>

tests/rustdoc/issue-112901-where-clause.assoc-Tr-impl-F.html

@@ -0,0 +1,3 @@
+<section id="associatedtype.F-1" class="associatedtype trait-impl"><a href="#associatedtype.F-1" class="anchor">&#167;</a><h4 class="code-header">type <a href="#associatedtype.F" class="associatedtype">F</a>&lt;T&gt; = T
+<span class="where">where
+    T: <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a></span></h4></section>

tests/rustdoc/issue-112901-where-clause.rs

@@ -0,0 +1,36 @@
+#![crate_name = "foo"]
+#![feature(trivial_bounds)]
+
+pub mod structs {
+    // @has foo/structs/struct.A.html
+    // @snapshot structs-A - '//pre[@class="rust item-decl"]'
+    pub struct A<T>(T)
+    where
+        T: Copy;
+
+    // @has foo/structs/struct.S.html
+    // @snapshot structs-S - '//pre[@class="rust item-decl"]'
+    pub struct S
+    where
+        String: Clone;
+}
+
+pub mod assoc {
+    // @has foo/assoc/struct.S.html
+    // @snapshot assoc-S-impl-F - '//section[@id="associatedtype.F"]'
+    pub struct S;
+
+    // @has foo/assoc/trait.Tr.html
+    // @snapshot assoc-Tr-decl - '//pre[@class="rust item-decl"]'
+    // @snapshot assoc-Tr-F - '//section[@id="associatedtype.F"]'
+    // @snapshot assoc-Tr-impl-F - '//section[@id="associatedtype.F-1"]'
+    pub trait Tr {
+        type F<T>
+        where
+            T: Clone;
+    }
+
+    impl Tr for S {
+        type F<T> = T where T: Clone;
+    }
+}

tests/rustdoc/issue-112901-where-clause.structs-A.html

@@ -0,0 +1,3 @@
+<pre class="rust item-decl"><code>pub struct A&lt;T&gt;(_)
+<span class="where">where
+    T: <a class="trait" href="{{channel}}/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a></span>;</code></pre>

tests/rustdoc/issue-112901-where-clause.structs-S.html

@@ -0,0 +1,3 @@
+<pre class="rust item-decl"><code>pub struct S
+<span class="where">where
+    <a class="struct" href="{{channel}}/alloc/string/struct.String.html" title="struct alloc::string::String">String</a>: <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a></span>;</code></pre>