Fix mapping of nullable generic underlying types of inline classes

#KT-32162 Fixed

compiler/testData/codegen/box/inlineClasses/genericUnderlyingValue/simple2.kt

@@ -0,0 +1,7 @@
+// CHECK_BYTECODE_LISTING
+// LANGUAGE: -JvmInlineValueClasses, +GenericInlineClassParameter
+// IGNORE_BACKED: JVM
+
+inline class ICAny<T: Any>(val value: T?)
+
+fun box(): String = ICAny("OK").value.toString()