[Test] Merge box against java testdata into codegen black box testsdata

compiler/testData/codegen/reflection/mapping/javaMethods.kt

@@ -0,0 +1,36 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// WITH_REFLECT
+// MODULE: lib
+// FILE: J.java
+
+public class J {
+    public String f(String s) {
+        return s;
+    }
+
+    public static String g(String s) {
+        return s;
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+import kotlin.reflect.*
+import kotlin.reflect.jvm.*
+
+fun box(): String {
+    val f = J::f
+    val fm = f.javaMethod ?: return "Fail: no Method for f"
+    if (fm.invoke(J(), "abc") != "abc") return "Fail fm"
+    val ff = fm.kotlinFunction ?: return "Fail: no KFunction for fm"
+    if (f != ff) return "Fail f != ff"
+
+    val g = J::g
+    val gm = g.javaMethod ?: return "Fail: no Method for g"
+    if (gm.invoke(null, "ghi") != "ghi") return "Fail gm"
+    val gg = gm.kotlinFunction ?: return "Fail: no KFunction for gm"
+    if (g != gg) return "Fail g != gg"
+
+    return "OK"
+}