[Wasm] Add @WasmImport annotation

Imports top-level function from given module

libraries/stdlib/wasm/src/kotlin/wasm/Annotations.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.wasm
+
+/**
+ * Imports a function from the given [module] with the given optional [name].
+ * The declaration name will be used if the [name] argument is not provided.
+ *
+ * Can only be used on top-level external functions.
+ *
+ * In JavaScript environment,
+ * function will be imported from ES module without type adapters.
+ */
+@Target(AnnotationTarget.FUNCTION)
+public annotation class WasmImport(
+    val module: String,
+    val name: String = ""
+)