When inflating Utf8 entries to BYTE state, we can use JavaLangAccess::countPositives and ArraysSupport::vectorizedHashCode to simplify the existing code with the same role.

In addition, when a String is created from BYTE state Utf8 entry, it can use the ISO_8859_1 encoding to bypass unnecessary checks for the UTF_8 encoding.

A new benchmark method is added to demonstrate the performance improvement, as the existing ReadMetadata::jdkReadName spends overwhelming majority of its time on Classfile structural parsing. The new benchmark spends about 50% CPU on creating strings from Utf8 entries and can show the effect of this patch more clearly.