[K/N] Add trivial test for RemoveRedundantSafepoints phase

kotlin-native/backend.native/tests/build.gradle

@@ -5931,6 +5931,7 @@ Task fileCheckTest(String name, Closure<FileCheckTest> configureClosure) {
                         if (!isCrossCompiling) {
                             extraOpts project.globalTestArgs
                         }
+                        extraOpts task.extraOpts
                         extraOpts "-Xtemporary-files-dir=$testOutputFileCheck/$name/$target"
                         extraOpts "-Xsave-llvm-ir-after=${task.phaseToCheck}"
                         if (lib != null) {
@@ -5975,6 +5976,14 @@ if (HostManager.@Companion.hostIsMac) {
         // LLVM might infer attributes.
         phaseToCheck = "BitcodeOptimization"
     }
+
+    fileCheckTest("filecheck_redundant_safepoints_removal") {
+        enabled = isExperimentalMM && project.globalTestArgs.contains("-opt")
+        annotatedSource = project.file('filecheck/redundant_safepoints.kt')
+        targetName = "watchos_arm32"
+        extraOpts = ["-Xbinary=memoryModel=experimental", "-opt"]
+        phaseToCheck = "RemoveRedundantSafepoints"
+    }
 }
 
 fileCheckTest("filecheck_replace_invoke_with_call") {

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: }
+}

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/FileCheckTest.kt

@@ -69,6 +69,9 @@ open class FileCheckTest : DefaultTask() {
     @get:Optional
     var additionalFileCheckFlags: List<String>? = null
 
+    @get:Input
+    var extraOpts: List<String> = emptyList()
+
     @get:Optional
     @get:Input
     var targetName: String = project.testTarget.name