[JS_IR] Use IrModuleFragment as input to lowering instead of iterable

This way we will be able to reuse existing utils
to create a lowering.

#KT-63073

js/js.tests/test/org/jetbrains/kotlin/benchmarks/GenerateIrRuntime.kt

@@ -611,7 +611,7 @@ class GenerateIrRuntime {
 
         ExternalDependenciesGenerator(symbolTable, listOf(jsLinker)).generateUnboundSymbolsAsDependencies()
 
-        jsPhases.invokeToplevel(phaseConfig, context, listOf(module))
+        jsPhases.invokeToplevel(phaseConfig, context, module)
 
         val transformer = IrModuleToJsTransformer(context, shouldReferMainFunction = false)