@JavaDebug annotation for the generation of toString()

When a structured parcelable is annotated with @JavaDebug, the generated
Java class for the parcelable has toString() implementation that can be
used for debugging purpose.

Bug: 150161123
Test: aidl_unittests
Test: atest aidl_integration_test
Change-Id: I5e7e911910b46c9c0e6bf09222225a6d2f57881f
diff --git a/aidl_language.h b/aidl_language.h
index 699880f..41c915a 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -220,6 +220,7 @@
     NULLABLE,
     UTF8_IN_CPP,
     JAVA_PASSTHROUGH,
+    JAVA_DEBUG,
   };
   static std::string TypeToString(Type type);
 
@@ -285,6 +286,7 @@
   bool IsVintfStability() const;
   bool IsStableApiParcelable(Options::Language lang) const;
   bool IsHide() const;
+  bool IsJavaDebug() const;
 
   void DumpAnnotations(CodeWriter* writer) const;