Basic inline class mapping to the underlying representation

core/descriptors/src/org/jetbrains/kotlin/resolve/inlineClassesUtils.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve
+
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
+
+fun ClassDescriptor.underlyingRepresentation(): ValueParameterDescriptor? {
+    if (!isInline) return null
+    return unsubstitutedPrimaryConstructor?.valueParameters?.singleOrNull()
+}