[FIR2IR] Generate fake-override symbols for functions

^KT-63644

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/symbols/impl/IrFakeOverrideSymbol.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.symbols.impl
+
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.declarations.IrProperty
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
+import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.utils.addToStdlib.shouldNotBeCalled
+
+abstract class IrFakeOverrideSymbolBase<S : IrBindableSymbol<D, I>, I : IrDeclaration, D : CallableDescriptor>(
+    val originalSymbol: S,
+    val containingClassSymbol: IrClassSymbol,
+    override val signature: IdSignature?
+) : IrBindableSymbol<D, I> {
+    @ObsoleteDescriptorBasedAPI
+    override val hasDescriptor: Boolean
+        get() = false
+
+    override val isBound: Boolean
+        get() = false
+
+    override var privateSignature: IdSignature?
+        get() = shouldNotBeCalled()
+        set(_) {
+            shouldNotBeCalled()
+        }
+
+    @UnsafeDuringIrConstructionAPI
+    @Deprecated("Fake-override symbols never has its owner", level = DeprecationLevel.HIDDEN)
+    override val owner: I
+        get() = shouldNotBeCalled()
+
+    @ObsoleteDescriptorBasedAPI
+    @Deprecated("Fake-override symbols never has its owner", level = DeprecationLevel.HIDDEN)
+    override val descriptor: D
+        get() = shouldNotBeCalled()
+
+    @Deprecated("Fake-override symbols never has its owner", level = DeprecationLevel.HIDDEN)
+    override fun bind(owner: I) {
+        shouldNotBeCalled()
+    }
+}
+
+class IrFunctionFakeOverrideSymbol(
+    originalSymbol: IrSimpleFunctionSymbol,
+    containingClassSymbol: IrClassSymbol,
+    idSignature: IdSignature?
+) : IrFakeOverrideSymbolBase<IrSimpleFunctionSymbol, IrSimpleFunction, FunctionDescriptor>(
+    originalSymbol, containingClassSymbol, idSignature
+), IrSimpleFunctionSymbol