Use Class.forName instead of ClassLoader.loadClass in reflection

This fixes an issue in constructing annotation instances with array
class elements. For some reason, behavior of `ClassLoader.loadClass`
differs from `Class.forName` in handling arrays, namely:

* `loadClass("[Ltest.Foo;")` returns null
* `Class.forName("[Ltest.Foo;")` returns class for array of test.Foo

Overall, there doesn't seem to be any way to load an array class with
`CLassLoader.loadClass`.

We pass initialize=false to forName because this is the behavior of
ClassLoader.loadClass: it doesn't perform class initialization (e.g.
<clinit> is not executed).

 #KT-31318 Fixed

core/reflection.jvm/src/kotlin/reflect/jvm/internal/util.kt

@@ -90,8 +90,8 @@ private fun loadClass(classLoader: ClassLoader, packageName: String, className:
     }
 
     var fqName = "$packageName.${className.replace('.', '$')}"
-    repeat(arrayDimensions) {
-        fqName = "[$fqName"
+    if (arrayDimensions > 0) {
+        fqName = "[".repeat(arrayDimensions) + "L$fqName;"
     }
 
     return classLoader.tryLoadClass(fqName)