Add a typeName() method to each type for error printing purposes.

Test: compiles with mma
Change-Id: I1283c395440282fde1106ad47aa185bdeda75880
diff --git a/EnumType.h b/EnumType.h
index ccdf384..09ad24d 100644
--- a/EnumType.h
+++ b/EnumType.h
@@ -40,6 +40,7 @@
 
     const ScalarType *resolveToScalarType() const override;
 
+    std::string typeName() const override;
     bool isEnum() const override;
 
     std::string getCppType(StorageMode mode,