DONT_MERGE: Turn on double inlining for Native
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/NativeLoweringPhases.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/NativeLoweringPhases.kt
index 96025ed..fc0ff1f 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/NativeLoweringPhases.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/NativeLoweringPhases.kt
@@ -605,7 +605,7 @@
         inlineCallableReferenceToLambdaPhase,
         arrayConstructorPhase,
         wrapInlineDeclarationsWithReifiedTypeParametersLowering,
-        inlineOnlyPrivateFunctionsPhase.takeIf { context.config.configuration.getBoolean(KlibConfigurationKeys.EXPERIMENTAL_DOUBLE_INLINING) },
+        inlineOnlyPrivateFunctionsPhase,
         // TODO KT-69174: the placeholder for synthetic accessors lowering
 )
 
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/TopLevelPhases.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/TopLevelPhases.kt
index 800cadb..4304f9d 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/TopLevelPhases.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/TopLevelPhases.kt
@@ -352,9 +352,7 @@
         // To avoid overcomplicating things and to keep running the preceding lowerings with "modify-only-lowered-file"
         // invariant, we would like to put a synchronization point immediately before "InlineAllFunctions".
         runLowerings(getLoweringsUpToAndIncludingSyntheticAccessors(), allModulesToLower)
-        if (context.config.configuration.getBoolean(KlibConfigurationKeys.EXPERIMENTAL_DOUBLE_INLINING)) {
-            runIrValidationPhase(validateIrAfterInliningOnlyPrivateFunctions, allModulesToLower)
-        }
+        runIrValidationPhase(validateIrAfterInliningOnlyPrivateFunctions, allModulesToLower)
         runLowerings(listOf(inlineAllFunctionsPhase), allModulesToLower)
     }
     runIrValidationPhase(validateIrAfterInliningAllFunctions, allModulesToLower)
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/NativeInlineFunctionResolver.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/NativeInlineFunctionResolver.kt
index 49c756c..36b6190 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/NativeInlineFunctionResolver.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/NativeInlineFunctionResolver.kt
@@ -97,9 +97,7 @@
         ArrayConstructorLowering(context).lower(body, function)
         WrapInlineDeclarationsWithReifiedTypeParametersLowering(context).lower(body, function)
 
-        if (context.config.configuration.getBoolean(KlibConfigurationKeys.EXPERIMENTAL_DOUBLE_INLINING)) {
-            NativeIrInliner(generationState, inlineOnlyPrivateFunctions = true).lower(body, function)
-        }
+        NativeIrInliner(generationState, inlineOnlyPrivateFunctions = true).lower(body, function)
 
         // TODO KT-69174: the placeholder for synthetic accessors lowering - it should generate accessors only for
         //  private declarations references from the lowered non-private inline function; the rest of IR file