PSI2IR KT-49526 function reference type approximation hack

compiler/testData/codegen/box/callableReference/kt49526.kt

@@ -0,0 +1,12 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR_STATUS: callable reference type approximation hack not implemented
+
+// WITH_STDLIB
+// CHECK_BYTECODE_LISTING
+
+inline fun <T> useRef(value: T, f: (T) -> Boolean) = f(value)
+
+fun box(): String {
+    val chars = listOf('a') + "-"
+    return if (useRef('a', chars::contains)) "OK" else "Failed"
+}

compiler/testData/codegen/box/callableReference/kt49526.txt

@@ -0,0 +1,6 @@
+@kotlin.Metadata
+public final class Kt49526Kt {
+    // source: 'kt49526.kt'
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+    public final static method useRef(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.jvm.functions.Function1): boolean
+}

compiler/testData/codegen/box/callableReference/kt49526_sam.kt

@@ -0,0 +1,35 @@
+// IGNORE_BACKEND: JVM
+// IGNORE_LIGHT_ANALYSIS
+
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR_STATUS: LambdaConversionException: Type mismatch for lambda argument 1: class java.lang.Object is not convertible to interface I1
+// JVM_IR it this case has an approximated type 'KFun<out Any>', which has a projected top-level argument.
+
+fun <T> intersect(x: T, y: T): T = x
+
+interface I1
+interface I2
+
+class C1 : I1, I2 {
+    override fun toString(): String = "OK"
+}
+
+class C2 : I1, I2
+
+fun <T> T.k() = K<T>(this)
+
+fun interface KFun<T> {
+    fun invoke(x: T)
+}
+
+class K<T>(private val x: T) {
+    fun with(kf: KFun<T>) {
+        kf.invoke(x)
+    }
+}
+
+fun box(): String {
+    var result = "Failed"
+    intersect(C1(), C2()).k().with { result = it.toString() }
+    return result
+}

compiler/testData/codegen/box/callableReference/kt49526a.kt

@@ -0,0 +1,20 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR_STATUS: callable reference type approximation hack not implemented
+
+fun <T> id(x: T): T = x
+
+fun <T> intersect(x: T, y: T): T = x
+
+interface I1
+interface I2
+
+class C1 : I1, I2 {
+    override fun toString() = "OK"
+}
+
+class C2 : I1, I2
+
+fun box() =
+    intersect(C1(), C2())
+        .let(::id)
+        .toString()

compiler/testData/codegen/box/callableReference/kt49526b.kt

@@ -0,0 +1,12 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR_STATUS: callable reference type approximation hack not implemented
+
+// WITH_STDLIB
+
+inline fun <T> useRef(value: T, f: (T) -> Boolean) = f(value)
+
+fun box(): String {
+    val chars = listOf('a') + "-"
+    val ref = chars::contains
+    return if (ref('a')) "OK" else "Failed"
+}