Migrate boxWithJava tests to multi-file framework

compiler/testData/codegen/boxWithJava/jvmName.kt

@@ -0,0 +1,23 @@
+// FILE: FakePlatformName.java
+
+import kotlin.jvm.JvmName;
+
+public class FakePlatformName {
+    @JvmName(name = "fake")
+    public String foo() {
+        return "foo";
+    }
+
+    public String fake() {
+        return "fake";
+    }
+}
+
+// FILE: FakePlatformName.kt
+
+fun box(): String {
+    val test1 = FakePlatformName().foo()
+    if (test1 != "foo") return "Failed: FakePlatformName().foo()==$test1"
+
+    return "OK"
+}