JS: refactor how last argument to suspend call is substituted

js/js.frontend/src/org/jetbrains/kotlin/js/descriptorUtils/descriptorUtils.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,7 +19,9 @@ package org.jetbrains.kotlin.js.descriptorUtils
 import com.intellij.openapi.util.text.StringUtil
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.descriptors.impl.AnonymousFunctionDescriptor
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.types.KotlinType
@@ -50,3 +52,6 @@ fun KotlinType.getJetTypeFqName(printTypeArguments: Boolean): String {
 }
 
 fun ClassDescriptor.hasPrimaryConstructor(): Boolean = unsubstitutedPrimaryConstructor != null
+
+val DeclarationDescriptor.isCoroutineLambda: Boolean
+    get() = this is AnonymousFunctionDescriptor && isCoroutine