Add test cases for tuples with links

src/test/rustdoc/tuples.link1_i32.html

@@ -0,0 +1 @@
+<code>pub fn tuple1(x: (<a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>,)) -&gt; (<a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>,)</code>

src/test/rustdoc/tuples.link1_t.html

@@ -0,0 +1 @@
+<code>pub fn tuple1_t&lt;T&gt;(x: <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T,)</a>) -&gt; <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T,)</a></code>

src/test/rustdoc/tuples.link2_i32.html

@@ -0,0 +1 @@
+<code>pub fn tuple2(x: (<a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>, <a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>)) -&gt; (<a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>, <a class="primitive" href="{{channel}}/std/primitive.i32.html">i32</a>)</code>

src/test/rustdoc/tuples.link2_t.html

@@ -0,0 +1 @@
+<code>pub fn tuple2_t&lt;T&gt;(x: <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T, T)</a>) -&gt; <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T, T)</a></code>

src/test/rustdoc/tuples.link2_tu.html

@@ -0,0 +1 @@
+<code>pub fn tuple2_tu&lt;T, U&gt;(x: <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T, U)</a>) -&gt; <a class="primitive" href="{{channel}}/std/primitive.tuple.html">(T, U)</a></code>

src/test/rustdoc/tuples.link_unit.html

@@ -0,0 +1 @@
+<code>pub fn tuple0(x: <a class="primitive" href="{{channel}}/std/primitive.unit.html">()</a>)</code>

src/test/rustdoc/tuples.rs

@@ -1,8 +1,20 @@
 #![crate_name = "foo"]
 
 // @has foo/fn.tuple0.html //pre 'pub fn tuple0(x: ())'
+// @snapshot link_unit - '//pre[@class="rust fn"]/code'
 pub fn tuple0(x: ()) -> () { x }
 // @has foo/fn.tuple1.html //pre 'pub fn tuple1(x: (i32,)) -> (i32,)'
+// @snapshot link1_i32 - '//pre[@class="rust fn"]/code'
 pub fn tuple1(x: (i32,)) -> (i32,) { x }
 // @has foo/fn.tuple2.html //pre 'pub fn tuple2(x: (i32, i32)) -> (i32, i32)'
+// @snapshot link2_i32 - '//pre[@class="rust fn"]/code'
 pub fn tuple2(x: (i32, i32)) -> (i32, i32) { x }
+// @has foo/fn.tuple1_t.html //pre 'pub fn tuple1_t<T>(x: (T,)) -> (T,)'
+// @snapshot link1_t - '//pre[@class="rust fn"]/code'
+pub fn tuple1_t<T>(x: (T,)) -> (T,) { x }
+// @has foo/fn.tuple2_t.html //pre 'pub fn tuple2_t<T>(x: (T, T)) -> (T, T)'
+// @snapshot link2_t - '//pre[@class="rust fn"]/code'
+pub fn tuple2_t<T>(x: (T, T)) -> (T, T) { x }
+// @has foo/fn.tuple2_tu.html //pre 'pub fn tuple2_tu<T, U>(x: (T, U)) -> (T, U)'
+// @snapshot link2_tu - '//pre[@class="rust fn"]/code'
+pub fn tuple2_tu<T, U>(x: (T, U)) -> (T, U) { x }