Delete generated test cases, move testData to boxWithStdlib

compiler/testData/codegen/boxWithStdlib/dataClasses/genericParam.kt

@@ -0,0 +1,12 @@
+data class A<T>(val x: T)
+
+fun box(): String {
+    val a = A(42)
+    if (a.component1() != 42) return "Fail a: ${a.component1()}"
+    
+    val b = A(239.toLong())
+    if (b.component1() != 239.toLong()) return "Fail b: ${b.component1()}"
+    
+    val c = A("OK")
+    return c.component1()
+}