[K2] Support proper serialization of string concatenation expressions

native/native.tests/testData/klibContents/builtinsSerializer/stringConcatenation.kt

@@ -0,0 +1,7 @@
+object Obj {
+    const val O = "O"
+    val concat = "${O}K"
+}
+
+@Deprecated("${Obj.O}/{id}")
+class Foo

native/native.tests/testData/klibContents/builtinsSerializer/stringConcatenation.txt

@@ -0,0 +1,6 @@
+package <root> {
+    @Deprecated(message = "O/{id}") class Foo constructor()
+    object Obj {
+        const val O: String = "O"
+        val concat: String = "OK"
+    }