JVM IR: remove obsolete -Xir-check-local-names

This flag was added a long time ago, at the time when we weren't sure if
we were going to keep the naming of local and anonymous classes
completely equal to the naming in the old backend. Now that we've
decided that we won't keep it equal and there are a lot of differences
already, it's not useful anymore.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt

@@ -374,8 +374,6 @@ private val jvmFilePhases = listOf(
     replaceKFunctionInvokeWithFunctionInvokePhase,
     kotlinNothingValueExceptionPhase,
 
-    checkLocalNamesWithOldBackendPhase,
-
     renameFieldsPhase,
     fakeInliningLocalVariablesLowering,
 

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/CheckLocalNamesWithOldBackend.kt

@@ -1,59 +0,0 @@
-/*
- * Copyright 2010-2019 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.backend.jvm.lower
-
-import org.jetbrains.kotlin.backend.common.FileLoweringPass
-import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
-import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
-import org.jetbrains.kotlin.codegen.binding.CodegenBinding
-import org.jetbrains.kotlin.config.JvmAnalysisFlags
-import org.jetbrains.kotlin.ir.IrElement
-import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
-import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrFile
-import org.jetbrains.kotlin.ir.util.render
-import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
-import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
-import org.jetbrains.kotlin.ir.visitors.acceptVoid
-
-val checkLocalNamesWithOldBackendPhase = makeIrFilePhase<JvmBackendContext>(
-    { context ->
-        if (context.state.languageVersionSettings.getFlag(JvmAnalysisFlags.irCheckLocalNames))
-            CheckLocalNamesWithOldBackend(context)
-        else
-            FileLoweringPass.Empty
-    },
-    name = "CheckLocalNamesWithOldBackend",
-    description = "With -Xir-check-local-names, check that names for local classes and anonymous objects are the same in the IR backend as in the old backend"
-)
-
-class CheckLocalNamesWithOldBackend(private val context: JvmBackendContext) : FileLoweringPass, IrElementVisitorVoid {
-    override fun lower(irFile: IrFile) {
-        irFile.acceptVoid(this)
-    }
-
-    @OptIn(ObsoleteDescriptorBasedAPI::class)
-    override fun visitClass(declaration: IrClass) {
-        val actualName = context.getLocalClassType(declaration)?.internalName
-        if (actualName != null) {
-            val expectedName = context.state.bindingTrace.get(CodegenBinding.ASM_TYPE, declaration.symbol.descriptor)?.internalName
-            if (expectedName != null && expectedName != actualName) {
-                throw AssertionError(
-                    "Incorrect name for the class.\n" +
-                            "IR: ${declaration.render()}\n" +
-                            "Descriptor: ${declaration.descriptor}\n" +
-                            "Expected name: $expectedName\n" +
-                            "Actual name: $actualName"
-                )
-            }
-        }
-        super.visitClass(declaration)
-    }
-
-    override fun visitElement(element: IrElement) {
-        element.acceptChildrenVoid(this)
-    }
-}