[Wasm] Support JsModule and JsQualifier

libraries/stdlib/wasm/src/kotlin/js/annotations.kt

@@ -37,4 +37,65 @@ public actual annotation class JsExport {
     AnnotationTarget.PROPERTY_GETTER,
     AnnotationTarget.PROPERTY_SETTER
 )
-public actual annotation class JsName(actual val name: String)
+public actual annotation class JsName(actual val name: String)
+
+/**
+ * Denotes an `external` declaration that must be imported from JavaScript module.
+ *
+ * The annotation can be used on top-level external declarations (classes, properties, functions) and files.
+ * In case of file (which can't be `external`) the following rule applies: all the declarations in
+ * the file must be `external`. By applying `@JsModule(...)` on a file you tell the compiler to import a JavaScript object
+ * that contain all the declarations from the file.
+ *
+ * Example:
+ *
+ * ``` kotlin
+ * @JsModule("jquery")
+ * external abstract class JQuery() {
+ *     // some declarations here
+ * }
+ *
+ * @JsModule("jquery")
+ * external fun JQuery(element: Element): JQuery
+ * ```
+ *
+ * @property import name of a module to import declaration from.
+ *           It is not interpreted by the Kotlin compiler, it's passed as is directly to the target module system.
+ */
+@Retention(AnnotationRetention.BINARY)
+@Target(AnnotationTarget.CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION, AnnotationTarget.FILE)
+public annotation class JsModule(val import: String)
+
+
+/**
+ * Adds prefix to `external` declarations in a source file.
+ *
+ * JavaScript does not have concept of packages (namespaces). They are usually emulated by nested objects.
+ * The compiler turns references to `external` declarations either to plain unprefixed names
+ * or to plain imports.
+ * However, if a JavaScript library provides its declarations in packages, you won't be satisfied with this.
+ * You can tell the compiler to generate additional prefix before references to `external` declarations using the `@JsQualifier(...)`
+ * annotation.
+ *
+ * Note that a file marked with the `@JsQualifier(...)` annotation can't contain non-`external` declarations.
+ *
+ * Example:
+ *
+ * ```
+ * @file:JsQualifier("my.jsPackageName")
+ * package some.kotlinPackage
+ *
+ * external fun foo(x: Int)
+ *
+ * external fun bar(): String
+ * ```
+ *
+ * @property value the qualifier to add to the declarations in the generated code.
+ *           It must be a sequence of valid JavaScript identifiers separated by the `.` character.
+ *           Examples of valid qualifiers are: `foo`, `bar.Baz`, `_.$0.f`.
+ *
+ * @see JsModule
+ */
+@Retention(AnnotationRetention.BINARY)
+@Target(AnnotationTarget.FILE)
+public annotation class JsQualifier(val value: String)