backend.native, runtime: implement @ExportTypeInfo

runtime/src/main/kotlin/kotlin_native/annotations.kt

@@ -1,5 +1,7 @@
 package kotlin_native
 
+// TODO: shouldn't these annotation be located in 'kotlin_native.internal' package?
+
 /**
  * Forces the compiler to use specified symbol name for the target `external` function.
  *
@@ -7,5 +9,12 @@ package kotlin_native
  * so it should probably be allowed on `internal` and `private` functions only.
  */
 @Target(AnnotationTarget.FUNCTION)
-@Retention(AnnotationRetention.BINARY)
+@Retention(AnnotationRetention.SOURCE)
 annotation class SymbolName(val name: kotlin.String)
+
+/**
+ * Exports the TypeInfo of this class by given name to use it from runtime.
+ */
+@Target(AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.SOURCE)
+annotation class ExportTypeInfo(val name: kotlin.String)