[FIR] Consider default values from expect function during serialization

It's not possible to unmute some tests for K2 because it causes testData structure changing

If change testData, NATIVE doesn't work even with `IGNORE_BACKEND`

compiler/testData/codegen/box/multiplatform/defaultArguments/functionFromOtherModule.kt

@@ -1,6 +1,6 @@
 // !LANGUAGE: +MultiPlatformProjects
 // IGNORE_BACKEND_K2: JVM_IR, JS_IR, NATIVE
-// FIR status: default argument mapping in MPP isn't designed yet
+// FIR status: expect/actual in the same module
 // WITH_STDLIB
 // MODULE: lib
 // FILE: common.kt

compiler/testData/codegen/box/multiplatform/defaultArguments/nestedEnumEntryValue.kt

@@ -2,7 +2,7 @@
 // IGNORE_BACKEND: JS_IR, JS_IR_ES6, WASM
 //  JS IR & Wasm: https://youtrack.jetbrains.com/issue/KT-51225
 // IGNORE_BACKEND_K2: JVM_IR, NATIVE
-// FIR status: default argument mapping in MPP isn't designed yet
+// FIR status: expect/actual in the same module
 // !LANGUAGE: +MultiPlatformProjects
 // MODULE: lib
 // FILE: common.kt