revert some type changes that are no longer needed

Author: erik-krogh

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -3219,7 +3219,7 @@ protected Node parseClass(Position startLoc, boolean isStatement) {
     Expression superClass = this.parseClassSuper();
     Position bodyStartLoc = this.startLoc;
     boolean hadConstructor = false;
-    List<MemberDefinition<?>> body = new ArrayList<>();
+    List<MemberDefinition<?>> body = new ArrayList<MemberDefinition<?>>();
     this.expect(TokenType.braceL);
     while (!this.eat(TokenType.braceR)) {
       if (this.eat(TokenType.semi)) continue;

javascript/extractor/src/com/semmle/js/ast/ClassBody.java

@@ -20,7 +20,7 @@ public void addMember(MemberDefinition<?> md) {
   }
 
   public MethodDefinition getConstructor() {
-    for (Node md : body) if (md instanceof MethodDefinition && ((MethodDefinition)md).isConstructor()) return (MethodDefinition) md;
+    for (MemberDefinition<?> md : body) if (md.isConstructor()) return (MethodDefinition) md;
     return null;
   }