JS: don't report about inline modifier on inline extension fun to external class

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/ExtensionFunctionToExternalIsInlinable.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2017 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.js.resolve
+
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.psi.KtCallableDeclaration
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.inline.ReasonableInlineRule
+
+object ExtensionFunctionToExternalIsInlinable : ReasonableInlineRule {
+    override fun isInlineReasonable(
+            descriptor: CallableMemberDescriptor,
+            declaration: KtCallableDeclaration,
+            context: BindingContext
+    ): Boolean {
+        val receiverParameter = descriptor.extensionReceiverParameter ?: return false
+        val receiverClass = receiverParameter.value.type.constructor.declarationDescriptor as? ClassDescriptor ?: return false
+        return DescriptorUtils.isEffectivelyExternal(receiverClass)
+    }
+}

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/JsPlatformConfigurator.kt

@@ -67,5 +67,6 @@ object JsPlatformConfigurator : PlatformConfigurator(
         container.useImpl<JsReflectionAPICallChecker>()
         container.useImpl<JsNativeRttiChecker>()
         container.useImpl<JsReifiedNativeChecker>()
+        container.useInstance(ExtensionFunctionToExternalIsInlinable)
     }
 }