refactor: merge annotation.py and local.py

vyper/semantics/analysis/common.py

@@ -12,8 +12,20 @@ def visit(self, node, *args):
             return
         node_type = type(node).__name__
         visitor_fn = getattr(self, f"visit_{node_type}", None)
-        if visitor_fn is None:
-            raise StructureException(
-                f"Unsupported syntax for {self.scope_name} namespace: {node_type}", node
-            )
-        visitor_fn(node, *args)
+        if visitor_fn:
+            visitor_fn(node, *args)
+            return
+
+        # iterate over the MRO until we find a matching visitor function
+        # this lets us use a single function to broadly target several
+        # node types with a shared parent
+        for class_ in node.__class__.mro():
+            ast_type = class_.__name__
+            visitor_fn = getattr(self, f"visit_{ast_type}", None)
+            if visitor_fn:
+                visitor_fn(node, *args)
+                return
+
+        raise StructureException(
+            f"Unsupported syntax for {self.scope_name} namespace: {node_type}", node
+        )