RFR: 8260245: Update ICU4C to version 68.2

[Arun Joseph]

On Mon, 5 Apr 2021 19:09:19 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

>> We currently use ICU4C version 64.2. We should update to the latest stable version 68.2.
>> http://site.icu-project.org/home
>
> Overall this looks good. I'll review / test it in detail later.
> 
> Quick comments on the PR:
> 
> 1. You need to update the version number in `.../legal/icu_web.md`
> 2. Related to the above, can you create a new `UPDATING.txt` file in `.../native/Source/ThirdParty/icu` with instructions as to what needs to be updated when updating to a new ICU version, specifically including the changes to `build.gradle`, `.../legal/icu_web.md`, and `/native/Source/ThirdParty/icu/CMakeLists.txt` regarding updating the version number, along with anything else that isn't obvious (although I think the rest is straight-forward)?
> 3. Will the changes in core WebKit code (e.g., `TRUE` --> `true`) cause merge conflicts in the future?
> 
> Also, since this also addresses [JDK-8232379](https://bugs.openjdk.java.net/browse/JDK-8232379), can you add it to this PR with `/issue add 8232379`?

The other WebKit changes are present in the upstream repo as well (https://bugs.webkit.org/show_bug.cgi?id=218522).

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

PR: https://git.openjdk.java.net/jfx/pull/456