FIR: Fix internal error on SAM with not-computed return type

^KT-52691 Fixed

compiler/testData/diagnostics/tests/samConversions/implicitReturnType.kt

@@ -0,0 +1,17 @@
+// FIR_IDENTICAL
+// SKIP_TXT
+// ISSUE: KT-52691
+
+fun test() = compose(C1())
+
+class C1 : FunInterface {
+    override fun invoke() = C2()()
+}
+
+class C2 : FunInterface {
+    override fun invoke() {}
+}
+
+fun interface FunInterface : () -> Unit
+
+fun compose(funInterfaces: FunInterface) = funInterfaces