refactor emitMemberName to be used more consistently

test/codegen/expect/opassign.js

Index: test/codegen/expect/opassign.js
diff --git a/test/codegen/expect/opassign.js b/test/codegen/expect/opassign.js
index e7b7c83ba807ef5508c579cf61b2c56417a0e497..98ed7397100c0560a48f70534462a1bdaf96ed3c 100644
--- a/test/codegen/expect/opassign.js
+++ b/test/codegen/expect/opassign.js
@@ -28,23 +28,23 @@ var opassign;
     let f = dart.map([0, 40]);
     core.print('should only call "index" 2 times:');
     let i = exports.index;
-    f.set(i, dart.dbinary(f.get(i), '+', 1));
+    f.set(i, dart.dsend(f.get(i), '+', 1));
     forcePostfix((() => {
       let i = exports.index, x$ = f.get(i);
-      f.set(i, dart.dbinary(x$, '+', 1));
+      f.set(i, dart.dsend(x$, '+', 1));
       return x$;
     })());
     core.print('should only call "foo" 2 times:');
     let o = exports.foo;
-    dart.dput(o, 'x', dart.dbinary(dart.dload(o, 'x'), '+', 1));
+    dart.dput(o, 'x', dart.dsend(dart.dload(o, 'x'), '+', 1));
     forcePostfix((() => {
       let o = exports.foo, x$ = dart.dload(o, 'x');
-      dart.dput(o, 'x', dart.dbinary(x$, '+', 1));
+      dart.dput(o, 'x', dart.dsend(x$, '+', 1));
       return x$;
     })());
     core.print('op assign test, should only call "index" twice:');
     let i = exports.index;
-    f.set(i, dart.dbinary(f.get(i), '+', f.get(exports.index)));
+    f.set(i, dart.dsend(f.get(i), '+', f.get(exports.index)));
   }
   // Function forcePostfix: (dynamic) → dynamic
   function forcePostfix(x) {