[js] Allow calling methods on a wrapped js function

Wrap js functions in a full class when passing them to Perl 6
land

src/vm/js/nqp-runtime/core.js

@@ -636,9 +636,7 @@ function fromJSToObject(ctx, obj) {
 }
 
 function fromJS(HLL, obj, isReturnValue, isArgument) {
-  if (typeof obj === 'function') {
-    return new WrappedFunction(obj);
-  } else if (obj === undefined || obj === null) {
+  if (obj === undefined || obj === null) {
     return HLL.get('null_value');
   } else if (obj === true) {
     return HLL.get('true_value');
@@ -672,6 +670,11 @@ function fromJS(HLL, obj, isReturnValue, isArgument) {
     return obj;
   } else {
     const type = HLL.get('js_box');
+
+    if (!type && typeof obj === 'function') {
+      return new WrappedFunction(obj);
+    }
+
     const wrapped = type.$$STable.REPR.allocate(type.$$STable);
     wrapped.$$jsObject = obj;
     return wrapped;

src/vm/js/nqp-runtime/reprs.js

@@ -2569,10 +2569,25 @@ class WrappedJSObject extends REPR {
   }
 
   setupSTable(STable) {
+    this.hardcodedInvokeSpec = true;
+
     STable.addInternalMethods(class {
       $$can(ctx, name) {
         return typeof this.$$jsObject[name] === 'function';
       }
+
+      /*async*/ $$apply(args) {
+        const converted = [];
+        for (let i = 2; i < args.length; i++) {
+          converted.push(/*await*/ core.toJSWithCtx(args[0], args[i]));
+        }
+        return core.fromJSToReturnValue(args[0], this.$$jsObject.apply(null, converted));
+      }
+
+      $$call(args) {
+        return this.$$apply(arguments);
+      }
+
     });
   }
 }

src/vm/js/nqp-runtime/sixmodel.js

@@ -198,6 +198,10 @@ class STable {
   }
 
   setinvokespec(classHandle, attrName, invocationHandler) {
+    if (this.REPR.hardcodedInvokeSpec) {
+      return;
+    }
+
     if (classHandle !== Null) {
       /* TODO  - think if we can use direct access here */
       const getter = this.REPR.getterForAttr(classHandle, attrName);