Fix IrFunction.isEmptyArray implementation

The previous one was incorrect for K1 since parent of top-level function
is `IrClass`, not `IrPackageFragment`.

The change is non-functional, K1 still worked correctly, but had to do
some extra work when inlining `emptyArray` calls and produces less
performant bytecode.

compiler/testData/codegen/box/script/syntheticJavaPropertyInScript.kt

@@ -1,6 +1,6 @@
 // TARGET_BACKEND: JVM_IR
 // IGNORE_LIGHT_ANALYSIS
-// JVM_ABI_K1_K2_DIFF: KT-62465, KT-63960
+// JVM_ABI_K1_K2_DIFF: KT-63960
 // LANGUAGE: +ReferencesToSyntheticJavaProperties
 // LANGUAGE: -SkipStandaloneScriptsInSourceRoots
 // WITH_STDLIB