[JS IR] Support setting custom module name (= unique name)

Required for #KT-36721.

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSCompilerArguments.kt

@@ -128,6 +128,13 @@ class K2JSCompilerArguments : CommonCompilerArguments() {
     @Argument(value = "-Xir-only", description = "Disables pre-IR backend")
     var irOnly: Boolean by FreezableVar(false)
 
+    @Argument(
+        value = "-Xir-module-name",
+        valueDescription = "<name>",
+        description = "Specify a compilation module name for IR backend"
+    )
+    var irModuleName: String? by NullableStringFreezableVar(null)
+
     @Argument(
         value = "-Xinclude",
         valueDescription = "<path>",