[IR] Simplify usage of IrOverrideUtil

It had some copy-pasted code for counting current file on each use-site.
Now it's encapsulated in strategy.

KT-61934

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/FakeOverrideBuilderStrategy.kt

@@ -40,6 +40,7 @@ abstract class FakeOverrideBuilderStrategy(
             else -> error("Unexpected fake override: $fakeOverride")
         }
     }
+    abstract fun inFile(file: IrFile?, block: () -> Unit)
 
     protected abstract fun linkFunctionFakeOverride(function: IrFunctionWithLateBinding, manglerCompatibleMode: Boolean)
     protected abstract fun linkPropertyFakeOverride(property: IrPropertyWithLateBinding, manglerCompatibleMode: Boolean)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.collectAndFilterRealOverrides
+import org.jetbrains.kotlin.ir.util.fileOrNull
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo
 import org.jetbrains.kotlin.types.AbstractTypeChecker
@@ -61,30 +62,32 @@ class IrOverridingUtil(
         }
 
     fun buildFakeOverridesForClass(clazz: IrClass, oldSignatures: Boolean) {
-        val superTypes = clazz.superTypes
+        fakeOverrideBuilder.inFile(clazz.fileOrNull) {
+            val superTypes = clazz.superTypes
 
-        val fromCurrent = clazz.declarations.filterIsInstance<IrOverridableMember>()
+            val fromCurrent = clazz.declarations.filterIsInstance<IrOverridableMember>()
 
-        val allFromSuper = superTypes.flatMap { superType ->
-            val superClass = superType.getClass() ?: error("Unexpected super type: $superType")
-            superClass.declarations
-                .filter { it.isOverridableMemberOrAccessor() }
-                .map {
-                    val overriddenMember = it as IrOverridableMember
-                    val fakeOverride = fakeOverrideBuilder.fakeOverrideMember(superType, overriddenMember, clazz)
-                    FakeOverride(fakeOverride, overriddenMember)
-                }
-        }
+            val allFromSuper = superTypes.flatMap { superType ->
+                val superClass = superType.getClass() ?: error("Unexpected super type: $superType")
+                superClass.declarations
+                    .filter { it.isOverridableMemberOrAccessor() }
+                    .map {
+                        val overriddenMember = it as IrOverridableMember
+                        val fakeOverride = fakeOverrideBuilder.fakeOverrideMember(superType, overriddenMember, clazz)
+                        FakeOverride(fakeOverride, overriddenMember)
+                    }
+            }
 
-        val allFromSuperByName = allFromSuper.groupBy { it.override.name }
+            val allFromSuperByName = allFromSuper.groupBy { it.override.name }
 
-        allFromSuperByName.forEach { group ->
-            generateOverridesInFunctionGroup(
-                group.value,
-                fromCurrent.filter { it.name == group.key && !it.isStaticMember },
-                clazz,
-                oldSignatures
-            )
+            allFromSuperByName.forEach { group ->
+                generateOverridesInFunctionGroup(
+                    group.value,
+                    fromCurrent.filter { it.name == group.key && !it.isStaticMember },
+                    clazz,
+                    oldSignatures
+                )
+            }
         }
     }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -1249,6 +1249,8 @@ private object BindToNewEmptySymbols : FakeOverrideBuilderStrategy(
             linkFunctionFakeOverride(it as? IrFunctionWithLateBinding ?: error("Unexpected fake override setter: $it"), manglerCompatibleMode)
         }
     }
+
+    override fun inFile(file: IrFile?, block: () -> Unit) { block() }
 }
 
 fun IrClass.addFakeOverrides(

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

@@ -86,6 +86,11 @@ private class IrLinkerFakeOverrideBuilderStrategy(
     friendModules = friendModules,
     unimplementedOverridesStrategy = unimplementedOverridesStrategy
 ) {
+
+    override fun inFile(file: IrFile?, block: () -> Unit) {
+        fakeOverrideDeclarationTable.inFile(file, block)
+    }
+
     override fun linkFunctionFakeOverride(function: IrFunctionWithLateBinding, manglerCompatibleMode: Boolean) {
         val (signature, symbol) = computeFunctionFakeOverrideSymbol(function, manglerCompatibleMode)
 
@@ -286,19 +291,11 @@ class IrLinkerFakeOverrideProvider(
 
         if (!platformSpecificClassFilter.needToConstructFakeOverrides(clazz)) return false
 
-        buildFakeOverridesForSingleClass(clazz, compatibilityMode)
+        irOverridingUtil.buildFakeOverridesForClass(clazz, compatibilityMode.oldSignatures)
 
         return true
     }
 
-    fun buildFakeOverridesForSingleClass(clazz: IrClass, compatibilityMode: CompatibilityMode) {
-        fakeOverrideDeclarationTable.run {
-            inFile(clazz.fileOrNull) {
-                irOverridingUtil.buildFakeOverridesForClass(clazz, compatibilityMode.oldSignatures)
-            }
-        }
-    }
-
     fun provideFakeOverrides(klass: IrClass, compatibilityMode: CompatibilityMode) {
         buildFakeOverrideChainsForClass(klass, compatibilityMode)
         haveFakeOverrides.add(klass)