RFR: 8272805: Avoid looking up standard charsets [v4]

[Sergey Bylokhov]

> This is the continuation of JDK-8233884, JDK-8271456, and JDK-8272120.
> 
> In many places standard charsets are looked up via their names, for example:
> absolutePath.getBytes("UTF-8");
> 
> This could be done more efficiently(up to x20 time faster) with use of java.nio.charset.StandardCharsets:
> absolutePath.getBytes(StandardCharsets.UTF_8);
> 
> The later variant also makes the code cleaner, as it is known not to throw UnsupportedEncodingException in contrary to the former variant.
> 
> This change includes:
>  * demo/utils
>  * jdk.xx packages
>  * Some places were missed in the previous changes. I have found it by tracing the calls to the Charset.forName() by executing tier1,2,3 and desktop tests.
> 
> Some performance discussion: https://github.com/openjdk/jdk/pull/5063
> 
> Code excluded in this fix: the Xerces library(should be fixed upstream), J2DBench(should be compatible to 1.4), some code in the network(the change there are not straightforward, will do it later).
> 
> Tested by the tier1/tier2/tier3 tests on Linux/Windows/macOS.

Sergey Bylokhov has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 16 additional commits since the last revision:

 - Merge branch 'master' into standard-encodings-in-non-public-modules
 - Merge branch 'master' into standard-encodings-in-non-public-modules
 - Update the usage of Files.readAllLines()
 - Update datatransfer
 - Merge branch 'master' into standard-encodings-in-non-public-modules
 - Merge branch 'master' into standard-encodings-in-non-public-modules
 - Fix related imports
 - Merge branch 'master' into standard-encodings-in-non-public-modules
 - Cleanup UnsupportedEncodingException
 - Update PacketStream.java
 - ... and 6 more: https://git.openjdk.java.net/jdk/compare/7289121a...7fe0327e

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5210/files
  - new: https://git.openjdk.java.net/jdk/pull/5210/files/79829ec8..7fe0327e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5210&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5210&range=02-03

  Stats: 949 lines in 30 files changed: 678 ins; 166 del; 105 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5210.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5210/head:pull/5210

PR: https://git.openjdk.java.net/jdk/pull/5210