RFR: 8299807: newStringNoRepl should avoid copying arrays for ASCII compatible charsets [v4]

[Glavo]

On Sat, 28 Jan 2023 19:54:32 GMT, Glavo <duke at openjdk.org> wrote:

>> This is the javadoc of `JavaLangAccess::newStringNoRepl`:
>> 
>> 
>>     /**
>>      * Constructs a new {@code String} by decoding the specified subarray of
>>      * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
>>      *
>>      * The caller of this method shall relinquish and transfer the ownership of
>>      * the byte array to the callee since the later will not make a copy.
>>      *
>>      * @param bytes the byte array source
>>      * @param cs the Charset
>>      * @return the newly created string
>>      * @throws CharacterCodingException for malformed or unmappable bytes
>>      */
>> 
>> 
>> It is recorded in the document that it should be able to directly construct strings with parameter byte array to reduce array allocation.
>> 
>> However, at present, `newStringNoRepl` always copies arrays for UTF-8 or other ASCII compatible charsets.
>> 
>> This PR fixes this problem.
>
> Glavo has updated the pull request incrementally with one additional commit since the last revision:
> 
>   update

Don't turn it off

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PR: https://git.openjdk.org/jdk/pull/12119