[KLIB] Drop API which is no longer used

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt

@@ -103,10 +103,6 @@ class CurrentModuleWithICDeserializer(
         icDeserializer.deserializeReachableDeclarations()
     }
 
-    override fun postProcess(postProcessor: (IrModuleFragment) -> Unit) {
-        icDeserializer.postProcess(postProcessor)
-    }
-
     private fun DeclarationDescriptor.isDirtyDescriptor(): Boolean {
         if (this is PropertyAccessorDescriptor) return correspondingProperty.isDirtyDescriptor()
         // Since descriptors for FO methods of `kotlin.Any` (toString, equals, hashCode) are Deserialized even in

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt

@@ -51,10 +51,6 @@ abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor) {
 
     open fun deserializeReachableDeclarations() { error("Unsupported Operation") }
 
-    open fun postProcess(postProcessor: (IrModuleFragment) -> Unit) {
-        postProcessor(moduleFragment)
-    }
-
     abstract val moduleFragment: IrModuleFragment
 
     abstract val moduleDependencies: Collection<IrModuleDeserializer>
@@ -174,10 +170,6 @@ class IrModuleDeserializerWithBuiltIns(
         else delegate.declareIrSymbol(symbol)
     }
 
-    override fun postProcess(postProcessor: (IrModuleFragment) -> Unit) {
-        delegate.postProcess(postProcessor)
-    }
-
     override fun init() {
         delegate.init(this)
     }
@@ -209,7 +201,5 @@ open class CurrentModuleDeserializer(
 
     override fun declareIrSymbol(symbol: IrSymbol) {}
 
-    override fun postProcess(postProcessor: (IrModuleFragment) -> Unit) {}
-
     override val isCurrent = true
 }