FIR: add status line to all failing black box tests

compiler/testData/codegen/box/ir/clashingFakeOverrideSignatures.kt

@@ -1,6 +1,6 @@
 // TARGET_BACKEND: JVM
 // IGNORE_BACKEND_FIR: JVM_IR
-//  ^ TODO decide if we want to fix KT-42020 for FIR as well
+// FIR status: validation failed. TODO decide if we want to fix KT-42020 for FIR as well
 
 open class Base<T> {
     fun foo(x: T) = "x:$x"

compiler/testData/codegen/box/ir/serializationRegressions/dispatchReceiverValue.kt

@@ -4,7 +4,7 @@
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // IGNORE_BACKEND_FIR: JVM_IR
-// ^ FIR doesn't support actualization in same module
+// FIR status: expect/actual in the same module (ACTUAL_WITHOUT_EXPECT)
 // MODULE: lib
 // FILE: common.kt
 

compiler/testData/codegen/box/ir/serializationRegressions/signatureClash.kt

@@ -5,6 +5,7 @@
 // IGNORE_BACKEND: JS_IR_ES6
 // IGNORE_BACKEND: NATIVE
 // IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: validation failed. TODO decide if we want to fix KT-42020 for FIR as well
 // MODULE: lib
 // FILE: lib.kt
 

compiler/testData/codegen/box/ir/serializationRegressions/varAsFunctionCall.kt

@@ -1,4 +1,5 @@
 // IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: ARGUMENT_TYPE_MISMATCH at ok.z(fail), actual String, expected T
 // MODULE: lib
 // FILE: l1.kt