[FE 1.0] Always create return value for CallInstruction

This fixes missing `USED_AS_EXPRESSION` recordings
^KT-47527 Fixed

compiler/testData/codegen/box/functions/kt47527.kt

@@ -0,0 +1,14 @@
+// ISSUE: KT-47527
+// WITH_STDLIB
+
+fun test_1(value: Any?): String? = value?.let { return "O" }
+fun test_2(value: Any?): String? = run {
+    value?.let { return "K" }
+}
+
+fun box(): String {
+    var result = ""
+    result += test_1(1) ?: return "fail 1"
+    result += test_2(1) ?: return "fail 2"
+    return result
+}