Merge boxMultiFile testData into box, delete BoxMultiFile test

compiler/testData/codegen/box/multifileClasses/inlineMultifileClassMemberFromOtherPackage.kt

@@ -0,0 +1,22 @@
+// WITH_RUNTIME
+// FILE: box.kt
+
+package test
+
+import a.foo
+
+fun box(): String = foo { "OK" }
+
+// FILE: foo.kt
+
+@file:[JvmName("A") JvmMultifileClass]
+package a
+
+inline fun foo(body: () -> String): String = zee(body())
+
+// FILE: zee.kt
+
+@file:[JvmName("A") JvmMultifileClass]
+package a
+
+public fun zee(x: String): String = x