add tests interleaving doc attrib comments and regular comments

Author: lqd

tests/source/doc-attrib.rs

@@ -18,12 +18,22 @@ mod tests {
         #[doc = "Level 3 comment"]
         fn f() {
             #[doc = "Level 4 comment"]
-            fn g() {                
+            fn g() {
             }
         }
     }
 }
 
+struct C {
+    #[doc = "item doc attrib comment"]
+    // regular item comment
+    b: i32,
+
+    // regular item comment
+    #[doc = "item doc attrib comment"]
+    c: i32,
+}
+
 // non-regression test for regular attributes, from #2647
 #[cfg(feature = "this_line_is_101_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")]
 pub fn foo() {}

tests/target/doc-attrib.rs

@@ -28,6 +28,16 @@ mod tests {
     }
 }
 
+struct C {
+    /// item doc attrib comment
+    // regular item comment
+    b: i32,
+
+    // regular item comment
+    /// item doc attrib comment
+    c: i32,
+}
+
 // non-regression test for regular attributes, from #2647
 #[cfg(
     feature = "this_line_is_101_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"