Extend interfaces.

Author: robrix

languages/tree-sitter-stack-graphs-java/src/stack-graphs.tsg

@@ -278,6 +278,10 @@ attribute node_symbol = node            => symbol = (source-text node), source_n
   edge @body.lexical_scope -> @this.lexical_scope
 }
 
+(interface_declaration (extends_interfaces (type_list (_) @type))) @this {
+  edge @type.lexical_scope -> @this.lexical_scope
+}
+
 (interface_body) @this {
   node @this.defs
   node @this.lexical_scope