dump_api: emits @deprecated in comments

Since @deprecated is an important part of versioned interfaces, we need
to emit them in API dumps so that clients of older versions are warned
when they use deprecated entities.

Bug: 177277347
Test: aidl_unittests
Merged-In: I65c97b85cb4e340d5f3feb3a23dabc078348ce8c
Change-Id: I65c97b85cb4e340d5f3feb3a23dabc078348ce8c
(cherry picked from commit ef1039bd8cd2407c470cce1c30ae6941313300c8)
diff --git a/aidl_language.h b/aidl_language.h
index 991bbe6..8604c34 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -435,6 +435,7 @@
   void SetComments(const std::string comments) { comments_ = comments; }
   bool IsHidden() const;
   bool IsDeprecated() const;
+  void Dump(CodeWriter& out) const;
 
  private:
   std::string comments_;
@@ -958,6 +959,7 @@
 
   virtual void Dump(CodeWriter* writer) const = 0;
   void DumpHeader(CodeWriter* writer) const;
+  void DumpMembers(CodeWriter& out) const;
 
   const std::vector<std::unique_ptr<AidlVariableDeclaration>>& GetFields() const {
     return variables_;