[K/N] Add trivial test for RemoveRedundantSafepoints phase

kotlin-native/backend.native/tests/filecheck/redundant_safepoints.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+import kotlin.native.Retain
+
+class C
+
+fun f(): Any {
+    return C()
+}
+
+fun g() = f()
+
+// CHECK-LABEL: define %struct.ObjHeader* @"kfun:#h(kotlin.Boolean){}kotlin.Any"
+@Retain
+fun h(cond: Boolean): Any {
+    // CHECK: Kotlin_mm_safePointFunctionPrologue
+    // CHECK-NOT: Kotlin_mm_safePointFunctionPrologue
+    // CHECK: br
+    if (cond) {
+        // CHECK: Kotlin_mm_safePointFunctionPrologue
+        // CHECK-NOT: Kotlin_mm_safePointFunctionPrologue
+        // CHECK: br
+        return listOf(C(), C())
+    } else {
+        // CHECK: Kotlin_mm_safePointFunctionPrologue
+        // CHECK-NOT: Kotlin_mm_safePointFunctionPrologue
+        return listOf(C(), C(), C())
+    }
+// CHECK: }
+}
+
+// CHECK-LABEL: define void @"kfun:#main(){}"()
+@Retain
+fun main() {
+    // CHECK: Kotlin_mm_safePointFunctionPrologue
+    // CHECK-NOT: Kotlin_mm_safePointFunctionPrologue
+    println(g())
+    println(h(true))
+// CHECK: }
+}