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/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JVMCompilerArguments.kt

@@ -88,12 +88,6 @@ class K2JVMCompilerArguments : CommonCompilerArguments() {
     @Argument(value = "-Xno-use-ir", description = "Do not use the IR backend. Useful for a custom-built compiler where IR backend is enabled by default")
     var noUseIR: Boolean by FreezableVar(false)
 
-    @Argument(
-        value = "-Xir-check-local-names",
-        description = "Check that names of local classes and anonymous objects are the same in the IR backend as in the old backend"
-    )
-    var irCheckLocalNames: Boolean by FreezableVar(false)
-
     @Argument(
         value = "-Xallow-unstable-dependencies",
         description = "Do not report errors on classes in dependencies, which were compiled by an unstable version of the Kotlin compiler"
@@ -446,7 +440,6 @@ class K2JVMCompilerArguments : CommonCompilerArguments() {
         result[JvmAnalysisFlags.inheritMultifileParts] = inheritMultifileParts
         result[JvmAnalysisFlags.sanitizeParentheses] = sanitizeParentheses
         result[JvmAnalysisFlags.suppressMissingBuiltinsError] = suppressMissingBuiltinsError
-        result[JvmAnalysisFlags.irCheckLocalNames] = irCheckLocalNames
         result[JvmAnalysisFlags.enableJvmPreview] = enableJvmPreview
         result[AnalysisFlags.allowUnstableDependencies] = allowUnstableDependencies || useFir
         result[JvmAnalysisFlags.disableUltraLightClasses] = disableUltraLightClasses