Remove generated codegen tests, move all testData to box/

A single test file will be generated out of box/ directory

compiler/testData/codegen/box/operatorConventions/compareTo/extensionArray.kt

@@ -0,0 +1,16 @@
+fun checkLess(x: Array<Int>, y: Array<Int>) = when {
+    x >= y    -> "Fail $x >= $y"
+    !(x < y)  -> "Fail !($x < $y)"
+    !(x <= y) -> "Fail !($x <= $y)"
+    x > y     -> "Fail $x > $y"
+    x.compareTo(y) >= 0 -> "Fail $x.compareTo($y) >= 0"
+    else -> "OK"
+}
+
+fun Array<Int>.compareTo(other: Array<Int>) = size - other.size
+
+fun box(): String {
+    val a = Array<Int>(0, {0})
+    val b = Array<Int>(1, {0})
+    return checkLess(a, b)
+}