Adds a debug(...) method to IBase, the base class for all Treble interfaces

The default implementation does nothing but this allows implementations to
emit diagnostics to a given file handle in a unified fashion.

Bug: 33961528
Test: hidl_test, hidl_test_java
Change-Id: Id7e8417275934c73032c9832c41e041d2d5d2fb7
diff --git a/Interface.h b/Interface.h
index a063902..376a78c 100644
--- a/Interface.h
+++ b/Interface.h
@@ -121,6 +121,7 @@
     bool fillUnlinkToDeathMethod(Method *method) const;
     bool fillSetHALInstrumentationMethod(Method *method) const;
     bool fillGetDebugInfoMethod(Method *method) const;
+    bool fillDebugMethod(Method *method) const;
 
     DISALLOW_COPY_AND_ASSIGN(Interface);
 };