Add tests showing how comments are handled

tests/source/type-alias-where-clauses-with-comments.rs

@@ -0,0 +1,31 @@
+type Foo // comment1
+ // interlinear1
+where // comment2
+ // interlinear2
+A: B, // comment3
+C: D, // comment4
+ // interlinear3
+= E; // comment5
+
+type Foo // comment6
+ // interlinear4
+where// comment7
+ // interlinear5
+A: B, // comment8
+C: D, // comment9
+ // interlinear6
+= E // comment10
+ // interlinear7
+where // comment11
+ // interlinear8
+F: G, // comment12
+H: I; // comment13
+
+type Foo // comment14
+ // interlinear9
+= E // comment15
+ // interlinear10
+where // comment16
+ // interlinear11
+F: G,// comment17
+H: I;// comment18

tests/target/type-alias-where-clauses-with-comments.rs

@@ -0,0 +1,39 @@
+type Foo
+// comment1
+// interlinear1
+where
+ // comment2
+ // interlinear2
+ A: B, // comment3
+ C: D, // comment4
+// interlinear3
+= E; // comment5
+
+type Foo
+// comment6
+// interlinear4
+where
+ // comment7
+ // interlinear5
+ A: B, // comment8
+ C: D, // comment9
+// interlinear6
+= E
+// comment10
+// interlinear7
+where
+ // comment11
+ // interlinear8
+ F: G, // comment12
+ H: I; // comment13
+
+type Foo // comment14
+ // interlinear9
+ = E
+// comment15
+// interlinear10
+where
+ // comment16
+ // interlinear11
+ F: G, // comment17
+ H: I; // comment18