Native: move samples to backend.native/tests/

kotlin-native/backend.native/tests/samples/workers/build.gradle.kts

@@ -0,0 +1,24 @@
+plugins {
+    kotlin("multiplatform")
+}
+
+kotlin {
+    // Determine host preset.
+    val hostOs = System.getProperty("os.name")
+
+    // Create target for the host platform.
+    val hostTarget = when {
+        hostOs == "Mac OS X" -> macosX64("workers")
+        hostOs == "Linux" -> linuxX64("workers")
+        hostOs.startsWith("Windows") -> mingwX64("workers")
+        else -> throw GradleException("Host OS '$hostOs' is not supported in Kotlin/Native $project.")
+    }
+
+    hostTarget.apply {
+        binaries {
+            executable {
+                entryPoint = "sample.workers.main"
+            }
+        }
+    }
+}