Add pp test for interleaving comments through vectors. Closes #679

Author: brson

src/test/pretty/vec-comments.pp

@@ -0,0 +1,29 @@
+// Issue #679
+// Testing that comments are correctly interleaved
+// pp-exact:vec-comments.pp
+fn main() {
+    let v1 =
+        ~[
+          // Comment
+          0,
+          // Comment
+          1,
+          // Comment
+          2];
+    let v2 =
+        ~[0, // Comment
+          1, // Comment
+          2]; // Comment
+    let v3 =
+        ~[
+          /* Comment */
+          0,
+          /* Comment */
+          1,
+          /* Comment */
+          2];
+    let v4 =
+        ~[0, /* Comment */
+          1, /* Comment */
+          2]; /* Comment */
+}

src/test/pretty/vec-comments.rs

@@ -0,0 +1,31 @@
+// Issue #679
+// Testing that comments are correctly interleaved
+// pp-exact:vec-comments.pp
+fn main() {
+    let v1 = ~[
+        // Comment
+        0,
+        // Comment
+        1,
+        // Comment
+        2
+    ];
+    let v2 = ~[
+        0, // Comment
+        1, // Comment
+        2  // Comment
+    ];
+    let v3 = ~[
+        /* Comment */
+        0,
+        /* Comment */
+        1,
+        /* Comment */
+        2
+    ];
+    let v4 = ~[
+        0, /* Comment */
+        1, /* Comment */
+        2  /* Comment */
+    ];
+}