[FIR] Disable failing blackbox codegen tests for FIR.

compiler/testData/codegen/box/privateConstructors/base.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor() {
     class Inner: Outer()

compiler/testData/codegen/box/privateConstructors/captured.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 public open class Outer private constructor(val s: String) {
 
     companion object {

compiler/testData/codegen/box/privateConstructors/companion.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor() {
     companion object {

compiler/testData/codegen/box/privateConstructors/inline.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor() {
     companion object {

compiler/testData/codegen/box/privateConstructors/inner.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor(val s: String) {
     inner class Inner: Outer("O") {

compiler/testData/codegen/box/privateConstructors/kt4860.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 open class A private constructor() {
     companion object : A() {
     }

compiler/testData/codegen/box/privateConstructors/synthetic.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_RUNTIME

compiler/testData/codegen/box/privateConstructors/withArguments.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor(val s: String, val f: Boolean = true) {
     class Inner: Outer("xyz")

compiler/testData/codegen/box/privateConstructors/withDefault.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor(val x: Int = 0) {
     class Inner: Outer()

compiler/testData/codegen/box/privateConstructors/withLinkedClasses.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor(val p: Outer?) {
     object First: Outer(null)

compiler/testData/codegen/box/privateConstructors/withVarargs.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // See also KT-6299
 public open class Outer private constructor(val s: String, vararg i: Int) {
     class Inner: Outer("xyz")