extensive rewrite of generation & execution of run-time initialization

src/script_opt/CPP/Attrs.h

@@ -0,0 +1,19 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+// Definitions associated with type attributes.
+
+#pragma once
+
+namespace zeek::detail
+	{
+
+enum AttrExprType
+	{
+	AE_NONE, // attribute doesn't have an expression
+	AE_CONST, // easy expression - a constant (ConstExpr)
+	AE_NAME, // easy - a global (NameExpr)
+	AE_RECORD, // an empty record cast to a given type
+	AE_CALL, // everything else - requires a lambda, essentially
+	};
+
+	} // zeek::detail