Migrate boxInline tests to new multi-file framework

compiler/testData/codegen/boxInline/reified/kt8047.kt

@@ -0,0 +1,16 @@
+// FILE: 1.kt
+
+package test
+
+inline fun <reified T> f(x : () -> Unit) {
+    object { init { arrayOf<T>() } }
+}
+
+// FILE: 2.kt
+
+import test.*
+
+fun box(): String {
+    f<String>() {}
+    return "OK"
+}