Move some tests from boxWithStdlib/ to box/

Move those tests which do not require neither stdlib nor reflect

compiler/testData/codegen/box/intrinsics/charToInt.kt

@@ -0,0 +1,8 @@
+fun box(): String {
+    val x: Any = 'A'
+    var y = 0
+    if (x is Char) {
+        y = x.toInt()
+    }
+    return if (y == 65) "OK" else "fail"
+}