Kill comments token in AidlMethod

Change-Id: I3df6629eaa5b56093d2453269d4b138987bee7ce
Test: unit tests
Bug: 24410295
Signed-off-by: Casey Dahlin <sadmac@google.com>
diff --git a/parse_helpers.cpp b/parse_helpers.cpp
index cca2021..c2f63e4 100644
--- a/parse_helpers.cpp
+++ b/parse_helpers.cpp
@@ -79,5 +79,20 @@
   return out;
 }
 
+std::string gather_comments(extra_text_type* extra) {
+  std::string s;
+  for (; extra; extra = extra->next) {
+    if (extra->which == SHORT_COMMENT) {
+      s += extra->data;
+    }
+    else if (extra->which == LONG_COMMENT) {
+      s += "/*";
+      s += extra->data;
+      s += "*/";
+    }
+  }
+  return s;
+}
+
 }  // namespace android
 }  // namespace aidl