Extract some codegen tests to black box testData

compiler/testData/codegen/box/casts/as.kt

@@ -0,0 +1,8 @@
+fun foo(x: Any) = x as Runnable
+
+fun box(): String {
+	val r = object : Runnable {
+		override fun run() {}
+	}
+	return if (foo(r) identityEquals r) "OK" else "Fail"
+}

compiler/testData/codegen/box/casts/asSafe.kt

@@ -0,0 +1,8 @@
+fun foo(x: Any) = x as? Runnable
+
+fun box(): String {
+	val r = object : Runnable {
+		override fun run() {}
+	}
+	return if (foo(r) identityEquals r) "OK" else "Fail"
+}

compiler/testData/codegen/box/casts/is.kt

@@ -0,0 +1,8 @@
+fun foo(x: Any) = x is Runnable
+
+fun box(): String {
+	val r = object : Runnable {
+		override fun run() {}
+	}
+	return if (foo(r) && !foo(42)) "OK" else "Fail"
+}

compiler/testData/codegen/box/casts/notIs.kt

@@ -0,0 +1,8 @@
+fun foo(x: Any) = x !is Runnable
+
+fun box(): String {
+	val r = object : Runnable {
+		override fun run() {}
+	}
+	return if (!foo(r) && foo(42)) "OK" else "Fail"
+}